JP2022103133A - Conductive composition and conductive film - Google Patents

Abstract

To provide a conductive composition having excellent dispersibility, and a conductive film having excellent conductivity and film strength.SOLUTION: A conductive composition contains a binder resin with an acid value of 10 mgKOH/g or more, and a boron-containing carbon material. The binder resin has an acid value of 10-100 mgKOH/g. The content of boron element in the boron-containing carbon material is 0.001-15 mol%.SELECTED DRAWING: None

Description

Embodiments of the present invention relate to conductive compositions and conductive films.

In recent years, the development of electronics has been remarkable, and conductive materials used in various electronic devices are also required to be smaller and lighter, cost lower, and have a longer life in various usage environments. For example, the board wiring of an electronic device and the wiring connecting an electronic device are generally formed by using a conductive composition using a metal filler such as silver or copper, which is a big problem in terms of cost. .. On the other hand, various studies have been made on conductive compositions using a conductive carbon material that does not use metal, but the conductivity is insufficient and the use is limited to semi-conductive applications such as antistatic applications. I came.

As one of the means for improving the conductivity of a carbon material, Patent Document 1 describes a carbon material containing boron. However, there is a problem that the conductivity cannot be sufficiently exhibited when the resin component or the like is dispersed in a dispersion medium and used. Further, in the system for cross-linking the coating film after coating the composition, there is a problem in the dispersion stability (stability with time) of the composition.

Further, Patent Document 2 describes a composition containing boron as a low resistance carbon material. However, the conductivity of the carbon material is not sufficient, and there is no description about the device for the combination of resins.

Further, Patent Document 3 describes a conductive composition characterized by containing a conductive carbon material and a synthetic resin having a specific acid value. However, the dispersibility, conductivity and film strength are not sufficient.

Japanese Patent No. 5680261 Japanese Unexamined Patent Publication No. 11-185751 Japanese Unexamined Patent Publication No. 2001-40233

It is an object of the present invention to provide a conductive composition having excellent dispersibility and coating suitability, and a conductive film having excellent conductivity and film strength, in view of the problems in the previous term.

The present invention has been made in view of the above problems, and relates to the following [1] to [6].

[1] A conductive composition containing a binder resin (A) having an acid value of 10 mgKOH / g or more and a boron-containing carbon material (B).

[2] The conductive composition according to [1], wherein the binder resin (A) has an acid value of 10 to 100 mgKOH / g.

[3] The conductive composition according to [1] or [2], wherein the boron-containing carbon material (B) has a boron element content of 0.001 to 15 mol%.

[4] The conductive composition according to [1] to [3], wherein the binder resin (A) contains at least one selected from the group consisting of polyurethane, polyamide and polyester.

[5] Any one of [1] to [4], wherein the mass ratio of the solid content of the binder resin (A) to the boron-containing carbon material (B) is 5:95 to 95: 5. The conductive composition according to the section.

[6] The conductivity according to any one of [1] to [5], wherein the boron-containing carbon material (B) contains at least one selected from the group consisting of graphite, carbon nanotubes, graphene nanoplatelets and graphene. Sex composition.

[7] A conductive film which is a coating film of the conductive composition according to any one of [1] to [6].

According to the present invention, by combining a boron-containing carbon material and a binder resin having a specific acid value, a conductive composition having excellent dispersibility and coating suitability, and excellent conductivity and film strength are obtained. A conductive film can be provided.
That is, according to the present invention, by combining a boron-containing carbon material and a binder resin having a specific acid value, the interface state between the conductive filler and the resin component can be optimized, and an excellent conductive network using the conductive filler can be used. It is possible to achieve both the formation of the resin film and the formation of a resin film having excellent strength.

The conductive composition of the present invention is characterized by containing a binder resin (A) having an acid value of 10 mgKOH / g or more and a boron-containing carbon material (B). Hereinafter, embodiments of the present invention will be described.

<Binder resin (A)>
The acid value of the binder resin (A) is 10 mgKOH / g or more, preferably 10 mgKOH / g to 100 mgKOH / g, more preferably 10 mgKOH / g to 60 mgKOH / g, and further preferably 10 mgKOH / g to 40 mgKOH / g. .. Within the above range, the boron-containing carbon material (B) described later can be satisfactorily dispersed, the formation of a conductive network is not hindered, and a conductive film having excellent film strength can be formed, which is preferable. This is because the amount of the binder resin (A) adsorbed on the boron-containing carbon material (B) is small, so that the contact resistance between the boron-containing carbon material (B) is reduced, the conductive network is effectively constructed, and the conductivity is increased. It is considered that a film having excellent properties is formed.
Further, since the excess binder resin (A) is not adsorbed on the boron-containing carbon material (B), it is considered that the proportion of the binder resin (A) that contributes to the coating strength increases and a conductive film having excellent film strength is formed. ..

The acid value of the binder resin (A) can be adjusted by the amount of the acidic functional group introduced. As the acidic functional group, at least one selected from the group consisting of a sulfonic acid group, a carboxylic acid group and a phosphoric acid group is preferable, and a carboxylic acid group is more preferable.
In the present specification, the acid value can be measured by a measuring method according to JIS K8574.

The binder resin (A) is not particularly limited, and is a polyurethane resin, a polyamide resin, an acrylonitrile resin, an acrylic resin, a butadiene resin, a polyvinyl resin, a polyvinyl butyral resin, a polyolefin resin, a polyester resin, and a polystyrene. It may contain one or more kinds selected from the group consisting of based resins, EVA resins, polyvinylidene fluoride resins, polytetrafluoroethylene resins, silicone resins, polyether resins, cellulose resins such as carboxymethyl cellulose and the like. can. The binder resin may be used alone or in combination of two or more.

From the viewpoint of volume resistivity, adhesion to the substrate, and durability, the binder resin (A) preferably contains at least one selected from the group consisting of polyurethane, polyamide, and polyester, and a polyurethane-based resin is more preferable. Further, the binder resin (A) is one that moderately softens or flows when the conductive composition is printed or coated on a substrate and then pressed or hot-pressed (hereinafter referred to as (heat) press). Is preferable. By using such a resin, the resin flows in the thickness direction while maintaining the planar pattern shape of the conductive film, the voids in the conductive film are reduced, and the contact points between the boron-containing carbon materials (B) are reduced. Therefore, a conductive film having a low volume resistivity can be obtained.

[Polyurethane resin]
The method for synthesizing the polyurentane resin is not particularly limited, and for example, a method for reacting a polyol compound (a) with a diisocyanate (b), a polyol compound (a), a diisocyanate (b), and a diol compound (c) having a carboxy group. To obtain a urethane prepolymer (d) having an isocyanate group, a method of further reacting the urethane prepolymer (d) with a polyamino compound (e), or a reaction as required in the above three cases. Examples thereof include a method of reacting a terminator.

(Polyform compound (a))
As the polyol compound (a), various polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene glycols, or a mixture thereof, which are generally known as polyol components constituting the polyurethane resin, are used. can.

Examples of the above-mentioned polyether polyols include polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran and the like.

Examples of the polyester polyols include, for example.
Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, hexane Saturated and unsaturated low molecular weight diols such as diols, octane diols, 1,4-butylene diols, diethylene glycols, triethylene glycols, dipropylene glycols and dimer diols, as well as n-butyl glycidyl ethers and 2-ethylhexyl glycidyl ethers. Monocarboxylic acid glycidyl esters such as alkyl glycidyl ethers and versatic acid glycidyl esters, and
Dicarboxylic acids such as adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, or anhydrous thereof. With things,
Examples thereof include polyester polyols obtained by dehydration condensation of the above, and polyester polyols obtained by ring-opening polymerization of a cyclic ester compound.

As the polycarbonate polyols, a reaction product of diol or bisphenol and a carbonic acid ester, and a reaction product of diol or bisphenol reacted with phosgene in the presence of an alkali can be used.

Examples of the carbonic acid ester include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, propylene carbonate and the like.
Examples of the diol include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, and 3,3'. -Dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9- Nonan diol, neopentyl glycol, octane diol, butyl ethyl pentane diol, 2-ethyl-1,3-hexane diol, cyclohexane diol, 3,9-bis (1,1-dimethyl-2-hydroxyethyl, 2,2) 8,10-Tetraoxospiro [5.5] Undecane and the like can be mentioned.
Examples of the bisphenol include bisphenol A, bisphenol F, and bisphenols obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to bisphenols.

The number average molecular weight (Mn) of the polyol compound (a) is appropriately determined in consideration of the solubility of the polyurethane resin in producing the conductive composition, the durability of the conductive film formed, the adhesive strength to the substrate, and the like. Although determined, it is usually preferably in the range of 580 to 8,000, more preferably 1,000 to 5,000.
The polyol compound (a) may be used alone or in combination of two or more. Further, as long as the performance of the polyurethane resin is not lost, a part of the polyol compound (a) can be replaced with low molecular weight diols, for example, various low molecular weight diols used for producing the polyol compound.

(Diisocyanate compound (b))
As the diisocyanate compound (b), for example, aromatic diisocyanate, aliphatic diisocyanate, alicyclic isocyanate, or a mixture thereof can be used.
Examples of the aromatic diisocyanate include 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-benzyl isocyanate, dialkyldiphenylmethane diisocyanate, and tetraalkyldiphenylmethane diisocyanate. Examples thereof include 1,3-phenylenediocyanate, 1,4-phenylenediocyanate, tolylene diisocyanate, and xylylene diisocyanate.
Examples of the aliphatic diisocyanate include butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate.
Examples of the alicyclic diisocyanate include cyclohexane-1,4-diisocyanate, isophorone diisocyanate, norbornane diisocyanatomethyl, bis (4-isocyanatecyclohexyl) methane, 1,3-bis (isocyanatemethyl) cyclohexane, and methylcyclohexanediisocyanate. Can be mentioned.
Isophorone diisocyanate is particularly preferable as the diisocyanate compound (b).

(Glycol compound (c) having a carboxy group)
Examples of the diol compound (c) having a carboxyl group include dimethylol alkanoic acid such as dimethylol acetic acid, dimethylol propionic acid, dimethylol butanoic acid and dimethylol pentanoic acid, dihydroxysuccinic acid and dihydroxybenzoic acid. In particular, dimethylol propionic acid and dimethylol butanoic acid are preferable from the viewpoint of reactivity and solubility.
The conditions for reacting the polyol compound (a) with the diisocyanate (b) and the diol compound (c) having a carboxy group to obtain the urethane prepolymer (d) having an isocyanate group are other than the excess of the isocyanate group. Although not particularly limited, the isocyanate group / hydroxyl group equivalent ratio is preferably in the range of 1.05 / 1 to 3/1. More preferably, it is 1.2 / 1 to 2/1. The reaction is usually carried out between room temperature and 150 ° C., and is preferably carried out between 60 and 120 ° C. in terms of production time and control of side reactions.

(Polyamino compound (e))
The polyamino compound (e) acts as a chain extender, and includes ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, norbornandiamine, and 2 -Amines having hydroxyl groups such as (2-aminoethylamino) ethanol, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, and di-2-hydroxypropylethylenediamine can be used. can. Among them, isophorone diamine is preferably used.

When synthesizing a polyurethane resin by reacting a urethane prepolymer (d) having an isocyanate group with a polyamino compound (e), a reaction terminator can be used in combination in order to adjust the molecular weight of the obtained polyurethane resin. As the reaction terminator, dialkylamines such as di-n-butylamine; dialkanolamines such as diethanolamine; alcohols such as ethanol and isopropyl alcohol can be used.

The conditions for reacting the urethane prepolymer (d) having an isocyanate group with the polyamino compound (e) and, if necessary, a reaction terminator are not particularly limited, but the free isocyanate groups at both ends of the urethane prepolymer are not particularly limited. When 1 equivalent is used, the total equivalent of the polyamino compound (e) and the amino group in the reaction terminator is preferably in the range of 0.5 to 1.3. More preferably, it is in the range of 0.8 to 0.995.
The weight average molecular weight of the polyurethane resin is preferably in the range of 5,000 to 200,000 from the viewpoint of coatability and handleability.

When synthesizing a polyurethane resin, one or two selected from ester-based solvents, ketone-based solvents, glycol ether-based solvents, aliphatic solvents, aromatic solvents, alcohol-based solvents, carbonate-based solvents, water, etc. The above can be used in combination.
Examples of the ester solvent include ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, ethyl lactate and the like.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone benzene, diisobutyl ketone, diacetone alcohol, isophorone, cyclohexanenone and the like.
Glycol ether-based solvents include ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, and acetates of these monoethers; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene. Examples thereof include glycol monomethyl ethers, propylene glycol monoethyl ethers, and acetates of these monoethers.
Examples of the aliphatic solvent include n-heptane, n-hexane, cyclohexane, methylcyclohexane, ethylcyclohexane and the like.
Examples of the aromatic solvent include toluene, xylene and the like.
Examples of the alcohol solvent include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, cyclohexanol and the like.
Examples of the carbonate solvent include dimethyl carbonate, ethylmethyl carbonate, di-n-butyl carbonate and the like.

[Polyamide resin]
Polypolymer resin is a general term for polymers having an amide bond obtained by various reactions such as polycondensation of dibasic acid and diamine, polycondensation of aminocarboxylic acid, or ring-opening polymerization of lactam, and includes various modified polyamides. , A polymer produced by a partially hydrogenated reaction product, and a polymer partially polycondensed with other monomers, or a mixture of other substances such as various additives can be used.
The polyamide-based resin is not particularly limited, but a dimer acid-modified polyamide resin obtained by condensation polymerization of a dibasic acid containing dimer acid as a main component and polyamines is preferable.

(Raw material for dimer acid-modified polyamide resin: dibasic acid)
As the dimer acid, dimer acid obtained by polymerizing a natural monobasic unsaturated fatty acid contained in tall oil fatty acid, soybean oil fatty acid, etc. is widely used industrially, but in principle, it is saturated fatty acid or unsaturated. Various dicarboxylic acids such as aliphatic, alicyclic, and aromatic dicarboxylic acids may be used.
Examples of commercially available products of the dimer acid include Hari Dimer 200, 300 (manufactured by Harima Chemicals, Inc.), Versa Dime 228, 216, Empole 1018, 1019, 1061, 1062 (manufactured by Cognis Co., Ltd.) and the like. Further, hydrogenated dimer acid can also be used, and examples of commercially available hydrogenated dimer acid include Prepole 1009 (manufactured by Croda Japan Co., Ltd.) and Empole 1008 (manufactured by Cognis Co., Ltd.).

In addition to the dimer acid, various dicarboxylic acids can be used as the dibasic acid in order to obtain a polyamide resin having appropriate flexibility. Examples of the dicarboxylic acid include oxalic acid, malonic acid, (anhydrous) succinic acid, (anhydrous) maleic acid, glutaric acid, adipic acid, bimeric acid, suberic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, and phthalic acid. Acids, naphthalenedicarboxylic acids, 1,3- or 1,4-cyclohexanedicarboxylic acids, 1,18-octadecanedicarboxylic acids, 1,16-hexadecanedicarboxylic acids and the like are used.
Further, a dibasic acid having a phenolic hydroxyl group can also be used. By using a dibasic acid having a phenolic hydroxyl group, the phenolic hydroxyl group can be introduced into the side chain of the polyamide resin and can be used for the reaction with the curing agent.
Examples of the dibasic acid having a phenolic hydroxyl group include hydroxyisophthalic acids such as 2-hydroxyisophthalic acid, 4-hydroxyisophthalic acid and 5-hydroxyisophthalic acid; 2,5-dihydroxyisophthalic acid and 2,4-dihydroxyisophthalic acid. Dihydroxyisophthalic acid such as acid, 4,6-dihydroxyisophthalic acid; dihydroxyterephthalic acid such as 2-hydroxyterephthalic acid, 2,3-dihydroxyterephthalic acid, 2,6-dihydroxyterephthalic acid; 4-hydroxyphthalic acid, 3- Hydroxyphthalic acid such as hydroxyphthalic acid; Dihydroxyphthalic acid such as 3,4-dihydroxyphthalic acid, 3,5-dihydroxyphthalic acid, 4,5-dihydroxyphthalic acid and 3,6-dihydroxyphthalic acid can be mentioned.
Further, these acid anhydrides, ester derivatives such as polybasic acid methyl ester, and the like may be used.
Of these, 5-hydroxyisophthalic acid is preferable from the viewpoint of copolymerizability, easy availability, and the like.

Further, various monocarboxylic acids are used as needed in order to obtain a polyamide resin having appropriate fluidity when heated. Examples of the monocarboxylic acid include propionic acid, acetic acid, caprylic acid (octanoic acid), stearic acid, and oleic acid.

(Raw material for dimer acid-modified polyamide resin: polyamines)
As the polyamines, for example, various diamines such as aliphatic, alicyclic and aromatic diamines, triamines and polyamines can be used.
Specific examples of the above diamines include ethylenediamine, propanediamine, butanediamine, triethylenediamine, tetraethylenediamine, hexamethylenediamine, p- or m-xylene diamine, 4,4'-methylenebis (cyclohexylamine), and 2,2-bis. -(4-Cyclohexylamine), polyglycoldiamine, isophoronediamine, 1,2-, 1,3- or 1,4-cyclohexanediamine, 1,4-bis- (2'-aminoethyl) benzene, N-ethyl Aminopiperazine, piperazine and the like can be mentioned.
Examples of the triamine include diethylenetriamine and the like, and examples of the polyamine include triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine and the like. Further, a dimer diamine obtained by converting a dimerized aliphatic nitrile group and reducing it with hydrogen can also be used.

Further, as the polyamine compound, a compound obtained by converting a carboniciki group of a polybasic acid compound having a cyclic or acyclic hydrocarbon group having 20 to 48 carbon atoms into an amino group may be used, and as a commercially available product, for example, Clauder. Examples thereof include "Priamine 1071", "Priamine 1073", "Priamine 1074" and "Priamine 1075" manufactured by Japan Co., Ltd. and "Versamine 551" manufactured by Cognis Japan Co., Ltd.

Alkanolamine may be used in combination with the diamine. Examples of the alkanolamine include ethanolamine, propanolamine, diethanolamine, butanolamine, 2-amino-2-methyl-1-propanol, 2- (2-aminoethoxy) ethanol and the like.

Further, as the diamine, a polyether diamine having an oxygen atom in the skeleton can be used. This polyether diamine can be expressed by the following general formula.
General formula: H ₂ N-R ^1- (RO) _n -R ² -NH ₂
(In the formula, n is 2 to 100, R ¹ and R ² are alkyl groups or alicyclic hydrocarbon groups having 1 to 14 carbon atoms, and R has 1 to 10 carbon atoms. It is an alkyl group or an alicyclic hydrocarbon group. The alkyl group may be linear or branched.)
Examples of such ether diamines include polyoxypropylene diamines, and commercially available products include Jeffamines (manufactured by San Techno Chemical Co., Ltd.). Further, bis- (3-aminopropyl) -polytetrahydrofuran can be used.

The polyamines and dimer acid or various dicarboxylic acids are heat-condensed by a conventional method and subjected to an amidation step accompanied by dehydration to produce various polyamide resins including dimer acid-modified polyamide resin. Generally, the reaction temperature is about 100 to 300 ° C., and the reaction time is about 1 to 8 hours.

[Polyester resin]
The polyester resin is a polymer composed of a polyvalent carboxylic acid and a polyhydric alcohol as a monomer. As the polyester resin, known ones can be adopted, and specifically, from the viewpoint of ensuring the cohesive force of the resin, the weight average molecular weight is preferably 1,000 to 100,000. Further, from the viewpoint of adhesion, the glass transition temperature is preferably −10 ° C. to 200 ° C.
Examples of the polyvalent carboxylic acid component include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, unsaturated dicarboxylic acids, and trivalent or higher carboxylic acids, and one or more of these can be selected and used. ..
Examples of the polyhydric alcohol component include aliphatic glycols, ether glycols, and trihydric or higher polyalcohols, and one or more of these can be selected and used.
Commercially available polyester resins include Byron (manufactured by Toyobo Co., Ltd., "Byron" is a registered trademark), Polyester (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., "Polyester" is a registered trademark), and Tesslac (Hitachi Kasei Polymer Co., Ltd.). , "Teslac" is a registered trademark) and the like.

The binder resin (A) is a polyether, polyester, polycarbonate, or a polyether, polyester, polycarbonate, or a material having a functional group capable of reacting with an isocyanate group from the viewpoints of fluidity at the time of heating, volume resistance, adhesion to a substrate, and durability. It is preferable to contain a vinyl-based polymer having at least one structure selected from polybutadiene in the side chain. The method for introducing the side chain is not particularly limited, and it can be obtained by various synthetic methods.

Examples of the functional group capable of reacting with the isocyanate group include a hydroxyl group, an amino group, a carboxy group, an epoxy group, an N-methylol group, an N-alkoxymethyl group and the like, and a hydroxyl group is preferably used in terms of reactivity.
The functional group capable of reacting with the isocyanate group can be introduced into the side chain or the main chain of the vinyl-based polymer, and the introduction method is not particularly limited, and can be introduced by various synthetic methods. When used in applications that require high toughness and durability, it is desirable to introduce a functional group capable of reacting with isocyanate directly into the backbone of the vinyl polymer, which can improve the crosslink density of the resin. ..

The polystyrene-equivalent weight average molecular weight of the vinyl polymer is preferably 5,000 to 500,000, more preferably 10,000 to 100,000. When the weight average molecular weight is 500,000 or less, the solubility in a solvent is improved, and when it is 5,000 or more, sufficient coating film strength is obtained after (heat) pressing.

<Crosslinking agent>
The binder resin (A) may be one that undergoes a curing (crosslinking) reaction after being coated on the substrate, or a curable resin may be used. Examples of the curable resin include resins having a functional group such as a hydroxyl group, a methylol group, a glycidyl group, an alicyclic epoxy group, a maleimide group, and a cyanate group.
The cross-linking agent used for the curable resin is not particularly limited, and examples thereof include polyisocyanate compounds having two or more isocyanate groups. The polyisocyanate compound is not particularly limited, and examples thereof include alicyclic, aliphatic or aromatic polyisocyanate compounds. When used outdoors, it is preferable to use only alicyclic or aliphatic compounds in order to prevent the coating film from deteriorating over time.

Examples of the alicyclic polyisocyanate compound include isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated 4,4'-diphenylmethane diisocyanate.
Examples of the aliphatic polyisocyanate compound include trimethylhexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, and lysine diisocyanate.
Examples of the aromatic polyisocyanate compound include diphenylmethane diisocyanate, toluylene diisocyanate, naphthylene-1,5-diisocyanate, o-xylene diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, triphenylmethane triisocyanate, and polymethylene polyphenyl. Examples include isocyanates.

As the polyisocyanate compound, a bi-terminal isocyanate adduct, a biuret modified product, or an isocyanurate modified product of the above-mentioned alicyclic, aliphatic or aromatic polyisocyanate compound and glycols or diamines may be used. ..
In particular, when the polyisocyanate compound contains an isocyanurate modified product, particularly an isocyanurate ring-containing triisocyanate, sufficient coating film strength can be obtained after hot pressing, which is preferable. Examples of the isocyanurate ring-containing triisocyanate include isocyanurate-modified isophorone diisocyanate (for example, Death Module Z4470 manufactured by Sumitomo Bayer Urethane Co., Ltd.) and isocyanurate-modified hexamethylene diisocyanate (for example, Sumijur N3300 manufactured by Sumitomo Bayer Urethane Co., Ltd.). , Isocyanurate-modified toluylene diisocyanate (for example, Sumijour FL-2, FL-3, FL-4, HLBA manufactured by Sumitomo Bayer Urethane Co., Ltd.) and the like.
The total number of isocyanate groups of the polyisocyanate compound can be appropriately adjusted according to the required performance, and is preferably 0.1 to 5.0 times, more preferably 0., with respect to the total number of functional groups of the binder resin (A). One kind or a mixture of two or more kinds can be used at a ratio of 5 times to 3.0 times, particularly preferably 0.8 to 2.0 times.

<Boron-containing carbon material (B)>
The boron-containing carbon material (B) is preferably a boron-containing carbon material doped so that the boron element replaces at least a part of the carbon element in the carbon skeleton. Such a carbon material has a carbon hexagonal network surface formed by covalently bonding carbon atoms in a hexagonal network as a basic skeleton, and has physical and chemical interactions (bonds) between these constituent units. However, at least the boron element is doped so as to replace a part of the carbon element. The boron-containing carbon material (B) may contain a hetero element such as a nitrogen element or a scale element, a base metal element, or the like, depending on the case.
Further, the form of boron in the boron-containing carbon material (B) is not particularly limited, and for example, a substituted boron element (BC ₃ type) in which the boron element is substituted at the position of the carbon element in the carbon skeleton, boron carbide. Type and Boron Cluster type Boron element ₍ B4 C type, Bc type), Boron oxide type boron element in a completely or partially oxidized state (BC ₂ O type, BCO ₂ type, B ₂ O ₃ type), etc. It may be either.
As such a boron-containing carbon material (B), one type may be used alone, or two or more types may be used in combination.

As will be described later, the boron-containing carbon material (B) improves the carrier density and / or mobility by boron-doping, so that the volume resistance of the powder is smaller than that of the non-boron-doped carbon material. Become. In addition, the surface state changes from the carbon material that is not boron-doped, and the wettability to, for example, a resin and a solvent tends to increase. Therefore, the binder resin (A) having an acid value of 10 mgKOH / g or more can disperse well, and further, it is possible to achieve both the formation of an excellent conductive network and the formation of a resin film having excellent strength. can.

The content of the boron element in the boron-containing carbon material (B) (the content of boron in the entire carbon material) is not particularly limited, but is preferably 0.001 to 15 mol%, and more preferably 0.01 to 2.5 mol%. It is preferable, and 0.1 to 1 mol% is particularly preferable. When it is in the range of 0.005 to 15 mol%, the effect of boron doping can be sufficiently obtained, and since the movement of electrons is not hindered by boron, good conductivity can be exhibited. Further, by containing boron, the affinity with organic solvents, dispersants, resins and the like is enhanced, and the dispersibility of the dispersion liquid is improved.
On the other hand, from the viewpoint of the strength and dispersibility of the carbon material, the boron content is preferably 2.5 mol% or less, and more preferably 1 mol% or less.

The content of boron in the boron-containing carbon material (B) can be determined by a method such as ICP emission spectroscopic analysis or ICP mass spectrometry. As an example, a measurement method conforming to JIS-R7223 can be mentioned. To calculate the mol% of the boron content, the mol number can be calculated from the mass of each element contained in the carbon material using the atomic weight of each element, and the mol% can be calculated from the mol ratio of each element. .. In the case of a boron-containing carbon material containing elements that cannot be measured by ICP emission spectroscopic analysis, etc., the mass of the contained elements and carbon elements is measured in combination with measurements such as element analysis, and the mol ratio and mol are measured from the atomic weight of each element. % Can be calculated. Normally, a boron-containing carbon material obtained by high-temperature heat treatment at 1000 ° C. or higher will volatilize or decompose most of the elements other than those that are difficult to volatilize or decompose, such as metals. Mol% can be calculated as a carbon element.

The boron-containing carbon material (B) preferably has a boron element content of 0.01 to 10 mol%, more preferably 0.01 to 1 mol%, as measured by X-ray photoelectron spectroscopy (XPS). preferable. When the ratio of the boron element is 0.01 to 10 mol%, a carbon material having excellent conductivity can be obtained. More preferably, it is 0.1 to 1 mol%. When the ratio of the boron element on the surface is 0.1 to 1 mol%, a carbon material having more excellent conductivity can be obtained.

Further, in the boron-containing carbon material (B), the ratio of the substituted boron element (BC type ₃ ) on the surface of the boron-containing carbon material measured by X-ray photoelectron spectroscopy (XPS) is preferably 0.01 to 6 mol%. , 0.01 to 1 mol% is more preferable. Since the substituted boron element (BC type ₃ ) has an effect of improving the carrier density, a carbon material having excellent conductivity can be obtained. The ratio of the substituted boron element on the surface of the carbon material was defined as the ratio B of the spectral area of the total boron element to the spectral area of all the elements on the surface of the carbon material measured by XPS, and was obtained from the B1s spectrum of XPS on the surface of the carbon material. When the ratio of the peak area of the substituted boron element to the spectral area of the total boron element is BR, it is expressed as _B × _BR .

It is known that the B1s spectrum of boron obtained by XPS measurement appears in the binding energy range of B1s electrons of the boron element (around 185 to 197 eV) and is roughly classified into four components. The value of the bond energy (peak top) of each component is 186 to 187 eV for boron clusters, 187 to 188 eV for boron carbide, and boron (BC ₃ ) doped so as to replace carbon elements having a hexagonal network as the basic skeleton. ) Appears in 188 to 189.3 eV, BC ₂ O which is various boron oxides appears in 189.5 to 190.5 eV, BCO ₂ appears in 191.5 to 192 eV, and B ₂ O ₃ appears in 192.5 to 193 eV. When these peaks overlap, the ratio can be obtained by performing fitting and separating the peaks by optimizing each component as a Gaussian function with the peak intensity, peak position, and full width at half maximum as parameters. can. Therefore, it is possible to perform peak separation of B1s and analyze the state of boron on the surface of the boron-doped carbon material.

The conductivity of the boron-containing carbon material (B) is represented by the following formula 1.
σ = μ × n × e (Equation 1)
μ: mobility, n: carrier density, e: elementary charge (constant)
According to the above (Equation 1), it is necessary to improve the mobility and / or the carrier density in order to improve the conductivity. By doping the carbon material with boron, the carrier density and / or mobility is improved, and a highly conductive carbon material can be obtained.

Examples of the carbon material in the boron-containing carbon material (B) include carbon black (furness black, acetylene black, ketjen black, medium thermal carbon black), graphite, carbon nanotubes, carbon nanofibers, carbon nanohorns, graphene, and graphene nanoplatelets. , Nanoporous carbon, carbon fiber and the like. These can be used alone or in combination of two or more.
From the viewpoint of conductivity, it is preferable to contain at least one selected from graphite, carbon nanotubes, graphene nanoplatelets, and graphene. Further, it is more preferable to use carbon black in combination with the above. As the carbon black used in combination with the above, Ketjen black is preferably used.

The boron-containing carbon material (B) is the ratio (IG / ID) of the peak intensities of the D band (1330-1370 cm ^-1 ) and the G band (1560-1620 cm ^-1 ) in the laser Raman spectrum having an excitation laser wavelength of 532 nm [. The G / D] ratio is preferably 0.5 or more.
When the carbon material in the boron-containing carbon material (B) is graphite, the [G / D] ratio is preferably 1.0 or more. When the [G / D] ratio is 1.0 or more, there are few defects on the carbon surface and crystal interfaces, and the electron conduction is excellent. The [G / D] ratio is preferably 1.25 or more, more preferably 1.7 or more, still more preferably 2.0 or more. The [G / D] ratio is preferably 7.0 or less, more preferably 5.0 or less.

The preferred range of the [G / D] ratio is 1.7 to 5.0, more preferably 2.0 to 5.0. Within the above range, when the conductive composition is produced, not only the conductivity is good, but also the wettability to the solvent and the binder resin is increased, and the hardness tends to increase. This improves durability against external forces such as impact, and improves dispersion stability and film strength.

When the carbon material in the boron-containing carbon material (B) is other than graphite, the preferable range of the [G / D] ratio is 0.5 to 5.0, and more preferably 0.6 to 2.0. ..

[Manufacturing method of boron-containing carbon material]
The method for producing the boron-containing carbon material (B) of the present invention is not particularly limited, but the step of mixing the carbon-based raw material (carbon source) and the boron-containing compound (boron source) and the early-stage mixture at 1000 ° C. or higher A method including a step of heat treatment at a high temperature is preferably used.

In the production of the boron-containing carbon material (B), the raw material composition ratio of the carbon-based raw material and the boron-containing compound is not particularly limited, but the ratio of the boron-containing compound to 100 parts by mass of the carbon-based raw material is preferably 0. It is 0.01 to 300 parts by mass, more preferably 0.1 to 100 parts by mass.

The mixture may contain at least a carbon-based raw material and a compound containing boron, and examples of the mixing method include dry mixing and wet mixing. As the mixing device, the following dry mixing device and wet mixing device can be used.

Dry mixers include, for example, roll mills such as two-roll and three-roll, high-speed stirrers such as Henshell mixers and super mixers, fluid energy crushers such as micronizers and jet mills, attritors, and particle composites manufactured by Hosokawa Micron. Devices such as "Nanocure", "Novirta", "Mechanofusion", powder surface reformer "Hybridation System", "Mechanomicros", and "Miraro" manufactured by Nara Machinery Co., Ltd. can be mentioned.
Further, when using a dry mixing device, two or more kinds of raw materials may be directly mixed as powders, but in order to prepare a more uniform mixture, one or more kinds of raw materials are previously dissolved in a small amount of solvent. Alternatively, a method of dispersing and mixing may be used. In order to further increase the processing efficiency, heating may be performed.

As the wet mixing device, for example, mixers such as a disper, a homomixer, or a planetary mixer, homogenizers such as "Clairemix" manufactured by M-Technique, or "Fillmix" manufactured by PRIMIX, and paint manufactured by Red Devil. Conditioner, ball mill, sand mills such as "Dyno Mill" manufactured by Symmal Enterprises, media type disperser such as attritor or coball mill, "Genus PY" manufactured by Genus, "Star Burst" manufactured by Sugino Machine, manufactured by Nanomizer. Wet jet mills such as "Nanmizer", medialess dispersers such as "Claire SS-5" manufactured by M-Technique, or "Micros" manufactured by Nara Kikai Seisakusho, or other roll mills and kneaders can be mentioned. , Not limited to these. Further, as the wet mixing device, it may be preferable to use a device that has been subjected to a metal contamination prevention treatment from the device.

For example, when using a media-type disperser, a method in which the agitator and vessel use a disperser made of ceramic or resin, or a disperser in which the surface of the metal agitator and vessel is treated with tungsten carbide spraying or resin coating. It is preferable to use. As the medium, it is preferable to use ceramic beads such as glass beads, zirconia beads, and alumina beads. Also, when using a roll mill, it is preferable to use a ceramic roll.
As the dispersive device, only one type may be used, or a plurality of types of devices may be used in combination.

When the raw materials are not uniformly dissolved, a general dispersant may be added together, dispersed and mixed in order to improve the wettability and dispersibility of each raw material in the solvent.
The dispersant used in the present invention effectively functions as a dispersant for each raw material, can alleviate the aggregation thereof, and is not particularly limited as long as it has the effect of alleviating the aggregation, and is conventionally known. You can use things. For example, a resin-type dispersant, a surfactant, and a dispersant of a pigment derivative can be used.
Examples of the resin type dispersant include a polyvinyl resin, a polyurethane resin, a polyester resin, a polyether resin, a cellulose resin such as carboxymethyl cellulose, a formalin condensate, a silicon resin, and a composite polymer thereof. Further, two or more kinds of these resin type dispersants may be used in combination. As the resin type dispersant, polyvinylpyrrolidone, polyvinyl alcohol, polystyrene sulfonic acid, polyacrylic acid, carboxymethyl cellulose and the like are preferable.

In the step of heat-treating the mixture, the heating temperature is preferably 1000 to 3200 ° C., more preferably 1500 to 3000 ° C., although it varies depending on the type and amount of the carbon-based raw material as a raw material and the compound containing boron. The heating time is not particularly limited, but is usually preferably 30 minutes to 10 hours.
Regarding the atmosphere in the heat treatment step, an inert gas atmosphere such as nitrogen or argon or a vacuum atmosphere is preferable in order to prevent oxidation of the raw material.
Further, regarding the heat treatment step, not only the method of performing the treatment in one step under a constant atmosphere and temperature, but also the heat treatment step may be performed in multiple steps by changing the atmosphere and temperature each time.

(Carbon-based raw material)
As the carbon-based raw material, an inorganic carbon-based raw material is preferable. Examples of inorganic carbon-based raw materials include graphite, carbon black (furness black, acetylene black, ketjen black, medium thermal carbon black), activated carbon, carbon nanotubes, carbon nanofibers, carbon nanohorns, graphene, graphene nanoplatelets, and nanoporous. Examples include carbon, carbon fiber, and charcoal. Among the above carbon-based raw materials, the size and laminated structure of the carbon hexagonal network vary depending on the type and manufacturer, and the crystallinity, particle size, shape, BET specific surface area, pore volume, pore diameter, bulk density, and DBP oil absorption amount. Since various physical properties such as surface acid basicity, surface hydrophilicity, and conductivity and costs are different, the optimum material can be selected according to the intended use and required performance.
The carbon-based raw material is not particularly limited, but preferably contains at least one selected from graphite, carbon nanotubes, graphene nanoplatelets, and graphene. Further, it is more preferable to use it in combination with carbon black.

"graphite"
Examples of graphite include artificial graphite and natural graphite. Artificial graphite is made by artificially orienting irregularly arranged micrographite crystals by heat treatment of amorphous carbon, and is generally produced using petroleum coke or coal-based pitch coke as the main raw material. .. As the natural graphite, flaky graphite such as flaky graphite, spherical graphite such as spheroidized graphite, scaly graphite such as scaly graphite and lump graphite, earthy graphite and the like can be used. It is also possible to use expanded graphite (also referred to as expandable graphite) obtained by chemically treating scaly graphite, or expanded graphite obtained by heat treatment and expansion of expanded graphite and then miniaturization or pressing. can.
Among these graphites, when used for a conductive coating film, natural graphite is preferable from the viewpoint of conductivity.

"Carbon black"
As carbon black, furnace black produced by continuously pyrolyzing gas or liquid raw materials in a reactor, especially acetylene black made from ethylene heavy oil, and the raw material gas are burned to burn the flame to the bottom of the channel steel. Various types such as channel black that has been rapidly cooled and precipitated, thermal black that is obtained by periodically repeating combustion and thermal decomposition using gas as a raw material, and acetylene black that uses acetylene gas as a raw material, alone or 2 It can be used in combination with more than one type. In addition, normally oxidized carbon black, hollow carbon, and the like can also be used.

Oxidation treatment of carbon is performed by treating carbon at a high temperature in the air or secondarily treating it with nitric acid, nitrogen dioxide, ozone, etc., for example, phenol group, quinone group, carboxyl group, carbonyl group, etc. It is a process of directly introducing (covalently bonding) an oxygen-containing polar functional group to the carbon surface, and is generally performed to improve the dispersibility of carbon. However, since the conductivity of carbon generally decreases as the amount of the functional group introduced increases, it is preferable to use carbon that has not been oxidized.

The carbon black used has a specific surface area (BET) obtained from the amount of adsorbed nitrogen, preferably 20 m ² / g or more and 1500 m ² / g or less, more preferably 50 m ² / g or more and 1500 m ² / g or less, more preferably. It is desirable to use 100 m ² / g or more and 1000 m ² / g or less, more preferably 150 m ² / g or more and 500 m ² / g or less. When the specific surface area is 20 m ² / g or more, sufficient conductivity is obtained, and when the specific surface area is 1500 m ² / g or less, commercially available products are easily available, which is preferable.

The particle size of carbon black is preferably 0.005 to 1 μm, more preferably 0.01 to 0.2 μm in terms of primary particle size. The primary particle diameter referred to here is an average of particle diameters measured by an electron microscope or the like.

Examples of commercially available carbon black include Tokai Carbon's Talker Black # 4300, # 4400, # 4500, # 5500, Degussa's Printex L, and Colombian's Raven 7000, 5750, 5250, 5000 ULTRA III, 500.
0ULTRA, ConductexSCULTRA, Conductex975ULTRA, PUERBACK100, 115, 205, Mitsubishi Chemical # 2350, # 2400B, # 2600B, # 3050B, # 3030B, # 3230B, # 3350B, # 3400B, # 5400B, Cabo 1300, 900, VulcanXC-72R, BlackPearls2000, Denkaco250G, Ensaco260G, Ensaco350G, SuperP-Li, etc. Examples thereof include acetylene black manufactured by Denka Black, Denka Black HS-100, FX-35 and the like, but the present invention is not limited to these, and two or more types may be used in combination.

《Carbon Fiber / Carbon Nanotube》
The carbon fiber has conductivity and is preferably obtained by firing from a petroleum-derived raw material, but can also be obtained by firing from a plant-derived raw material.
Carbon nanotubes include single-walled carbon nanotubes in which graphene sheets form a tube having a diameter in the nanometer region, and multi-walled carbon nanotubes in which graphene sheets are multi-walled. Therefore, the diameter of the multi-walled carbon nanotubes is as large as 30 nm with respect to 0.7-2.0 nm of a typical single-walled carbon nanotube.

Examples of commercially available conductive carbon fibers and carbon nanotubes include vapor-phase carbon fibers such as VGCF manufactured by Showa Denko Co., Ltd., and EC1.0, EC1.5, EC2.0, and EC1.5- manufactured by Meijo Nanocarbon Co., Ltd. Examples thereof include single-walled carbon nanotubes such as P, FloTube9000 manufactured by CNano, FloTube9100, FloTube9110, FloTube9200, NC7000 manufactured by Nanocyl, and 100T manufactured by Knano.
Examples of commercially available graphene-based carbons include graphene nanoplatelets xGnP-C-300, xGnP-C-500, xGnP-C-750, xGnP-M-5, xGnP-M-15, xGnP-M manufactured by XGSciences. -25, xGnP-H-5, xGnP-H-15, xGnP-H-25, but are not limited thereto.
From the viewpoint of conductivity and cost, carbon black is preferable as a commercially available carbon-based raw material.

As the carbon-based raw material, not only the inorganic carbon-based raw material but also an organic carbon-based raw material which is an organic material that becomes carbon particles after heat treatment can be used. Specific organic materials include phenolic resin, polyimide resin, polyamide resin, polyamideimide resin, polyacrylonitrile resin, polyaniline resin, phenolformaldehyde resin resin, polyimidazole resin, polypyrrole resin, and poly. Examples thereof include benzoimidazole-based resins, melamine-based resins, pitch, coke, brown charcoal, polycarbodiimide, biomass, proteins, fumic acid and the like, and derivatives thereof. Of these, it is preferable to use coke or pitch, which is also used as a raw material for graphite.

(Compound containing boron)
Next, a boron-containing compound used for producing a boron-containing carbon material will be described.
The boron-containing compound is not particularly limited, but is boron carbide such as B ₄ C (B ₁₂ C ₃ ), B ₁₂ C ₂ (B ₆ C); BC ₂ O, BCO ₂ , B ₂ O ₂ , B ₂ O. ₃ , Boron oxide such as B ₄ O ₃ , B ₄ O ₅ ; Boron nitride such as BN; Metal boric acid such as AlB ₂ , CoB, FeB, MgB ₂ , NiB, TiB ₂ ; Orthoboric acid, Metaboric acid, Tetraboric acid Boron oxo acids such as acids; Boran such as monoboran, diboran, decabolan; boric acids such as trimethyl borate and triethyl borate, substituted boranes such as triethylboran and triphenylboran, phenylboronic acid and phenylboronic acid esters Boron-containing organic compounds such as boric acids and the like;

The mass ratio of the binder resin (A) to the boron-containing carbon material (B) is preferably 5:95 to 95: 5, and more preferably 40:60 to 10:90. Within the above range, a conductive film having excellent adhesion can be obtained, and a conductive film having high conductivity and film strength without the binder resin hindering contact between carbon materials in the conductive film. can get.

<Solvent>
The conductive composition of the present invention may contain a solvent, if necessary. The solvent is used as a dissolving or dispersion medium for the binder resin (A) and the boron-containing carbon material (B), and can improve the coatability by inking. The solvent that can be used may be any solvent as long as the binder resin (A) and the boron-containing carbon material (B) can be dissolved or dispersed, and examples thereof include organic solvents and water, and two or more kinds may be used in combination. ..
Examples of the organic solvent include alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol methyl ether and diethylene glycol methyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; tetrahydrofuran, dioxane and ethylene glycol dimethyl ether, Ethers such as diethylene glycol dimethyl ether; Hydrocarbons such as hexane, heptane and octane; Fragrances such as benzene, toluene, xylene and cumene; Esters such as ethyl acetate and butyl acetate; Tarpineol, dihydroterpineol, 2,4- Diethyl-1,5-
Examples thereof include pentanediol, 1,3-butylene glycol, isobornylcyclohexanol, dimethyl sulfoxide, dimethylformamide, and N-methylpyrrolidone, which can be appropriately selected as needed.
The solvent is preferably a mixed solvent of toluene and propanol, dimethylformamide, N-methylpyrrolidone, and more preferably a mixed solvent of toluene and propanol.

<Other ingredients>
The conductive composition of the present invention may contain a conductive auxiliary agent other than the boron-containing carbon (B), and a wide range of carbon materials may be combined. Examples of such a conductive auxiliary agent include metals used in conductive applications such as copper and silver as metal materials.
Further, the conductive composition of the present invention can be used as an ultraviolet absorber, an ultraviolet stabilizer, a radical catching agent, a filler, a thixotropy-imparting agent, an antiaging agent, and an oxidation, if necessary, as long as the effects of the present invention are not impaired. Antiseptic, antistatic, flame retardant, thermal conductivity improver, plasticizer, anti-sagging agent, antifouling agent, preservative, bactericidal agent, defoamer, leveling agent, blocking inhibitor, hardening agent, thickener , Dispersants, silane coupling agents and the like may be added.

<Distributor / Mixer>
As an apparatus used for obtaining a conductive material composition, a disperser or a mixer usually used for pigment dispersion or the like can be used, and for example, mixers such as a disper, a homomixer, or a planetary mixer; M-Technique Co., Ltd. Homogenizers such as "Clairemix" manufactured by PRIMIX or "Philmix" manufactured by PRIMIX; paint conditioner (manufactured by Red Devil), ball mill, sand mill ("Dynomill" manufactured by Simmal Enterprises, etc.), attritor, pearl mill (Eich) Media type disperser such as "DCP mill" manufactured by Coball Mill; wet jet mill ("Genus PY" manufactured by Genus, "Starburst" manufactured by Sugino Machine, "Nanomizer" manufactured by Nanomizer, etc.), M-Technique Medialess dispersers such as "Claire SS-5" manufactured by Nara Machinery Co., Ltd .; or other roll mills, but are not limited thereto.

For example, when using a media-type disperser, a method in which the agitator and vessel use a disperser made of ceramic or resin, or a disperser in which the surface of the metal agitator and vessel is treated with tungsten carbide spraying or resin coating. It is preferable to use. As the medium, it is preferable to use glass beads, zirconia beads, or ceramic beads such as alumina beads. As the dispersive device, only one type may be used, or a plurality of types of devices may be used in combination.

<Condensate>
A conductive film can be formed by the conductive material composition of the present invention. The method for forming the conductive film is not particularly limited, and for example, a conductive material composition containing a solvent can be applied and dried on a substrate to form the conductive film.

(Base material)
The shape of the base material used for forming the conductive film is not particularly limited, but it is preferably in the form of a sheet. Further, an insulating resin film is preferable, and one suitable for various uses can be appropriately selected. For example, examples of the material include PET (polyethylene terephthalate), PEN (polyethylene naphthalate), polyimide, polyvinyl chloride, polyamide, nylon, OPP (stretched polypropylene), CPP (unstretched polypropylene) and the like, but are particularly limited. There is no such thing.
As the shape of the base material, a film on a flat plate is generally used, but a roughened surface, a primer-treated one, a perforated one, and a mesh-like base material are also used. can.

The method for applying the conductive composition on the substrate is not particularly limited, and a known method can be used. Specific examples thereof include a die coating method, a dip coating method, a roll coating method, a doctor coating method, a knife coating method, a spray coating method, a gravure coating method, a screen printing method, an electrostatic coating method, and the like, and a drying method. Examples thereof include a stand-alone dryer, a blower dryer, a warm air dryer, an infrared heater, a far infrared heater, and the like, but the present invention is not particularly limited thereto.
Further, after coating, a rolling process such as a lithographic press or a calendar roll may be performed, or may be performed while heating in order to soften the conductive film and facilitate pressing. The thickness of the conductive film is generally 0.1 μm or more and 1 mm or less, preferably 1 μm or more and 200 μm or less.

A laminate having a conductive film formed from the conductive composition of the present invention on a substrate has excellent conductivity, durability, and smoothness, and has excellent conductivity, durability, smoothness, conductive wiring, an antenna material for RFID, and electromagnetic shielding. It can be suitably used for applications such as materials, materials for sensors, conductive materials for secondary batteries, and conductive materials for fuel cells.

Hereinafter, the present invention will be described in more detail with reference to experimental examples. In the example, "part" means "part by mass", and "%" means "% by mass".

<Number average molecular weight (Mn), weight average molecular weight (Mw)>
The number average molecular weight and the weight average molecular weight were measured by gel permeation chromatography (GPC) and converted into polystyrene. The definitions of Mn and Mw are described in "Basics of Polymer Chemistry" (edited by the Society of Polymer Chemistry, Tokyo Kagaku Dojin, 1978) and JIS-J7252-1, etc., and can be calculated from the molecular weight distribution curve by GPC. ..

<Acid value (AV), hydroxyl value (OHV)>
The acid value and the hydroxyl value were measured by the potentiometric titration method. As the measuring method, a measuring method based on JIS-K0070-1992 was used.

<Boron element content (mol%)>
The boron element content is the content (atomic composition percentage) of the boron element in the boron-containing carbon material (B), which is derived from the ratio of the boron element in the boron-containing carbon material measured by ICP emission spectroscopic analysis. be.

<G / D ratio>
The G / D ratio was measured using a laser Raman spectrophotometer NRS-3100 manufactured by Nippon Kogaku Co., Ltd. under the condition of an excitation laser wavelength of 532 nm, and the D band (1330-1370 cm ^-1 ) of the Raman spectrum of each sample obtained was obtained. ) And the peak intensity ratio (IG / ID) of the G band (1560-1620 cm ^-1 ), the G / D ratio was calculated.

<Synthesis of binder resin (A)>
(Synthesis Example 1) Synthesis of Urethane Urea Resin A-1 (Resin Acid Value 10 mgKOH / g)
Polyester polyol (manufactured by Kuraray Co., Ltd.) obtained from terephthalic acid, adipic acid and 3-methyl-1,5-pentanediol in a reaction vessel equipped with a stirrer, a thermometer, a reflux cooler, a dropping device, and a nitrogen introduction tube. "Kurare Polyol P-2011", Mn = 2011) 198.0 parts, 6.5 parts of dimethylolbutanoic acid, 40.2 parts of isophorone diisocyanate, 110 parts of toluene were charged and reacted at 90 ° C. for 3 hours under a nitrogen atmosphere. Toluene was added to 220 parts of toluene to obtain a urethane prepolymer solution having an isocyanate group. Next, a mixture of 1.74 parts of isophoronediamine, 0.17 parts of di-n-butylamine, 44 parts of 2-propanol and 68 parts of toluene was mixed with 534.7 parts of the obtained urethane prepolymer solution having an isocyanate group. A-1 is a urethane urea resin having an acid value of 10 mgKOH / g and a weight average molecular weight of 61,000. Got

(Synthesis Example 2) Synthesis of Urethane Urea Resin A-2 (Resin Acid Value 20 mgKOH / g)
Polyester polyol obtained from terephthalic acid, adipic acid and 3-methyl-1,5-pentanediol in a reaction vessel equipped with a stirrer, a thermometer, a reflux cooler, a dropping device, and a nitrogen introduction tube (manufactured by Kuraray Co., Ltd.) "Kurare Polyester P-2011", Mn = 2011) 179.1 parts, dimethylol butanoic acid 12.93 parts, isophorone diisocyanate 50.2 parts, toluene 110 parts were charged and reacted at 90 ° C. for 3 hours under a nitrogen atmosphere. Toluene was added to 220 parts of toluene to obtain a urethane prepolymer solution having an isocyanate group. Next, a mixture of 1.58 parts of isophoronediamine, 0.16 parts of di-n-butylamine, 44 parts of 2-propanol and 68 parts of toluene was mixed with 534.7 parts of the obtained urethane prepolymer solution having an isocyanate group. Binder resin A-2, which is a urethane urea resin having an acid value of 20 mgKOH / g and a weight average molecular weight of 58,000, is reacted at 50 ° C. for 3 hours and then at 70 ° C. for 2 hours, and then vacuum-dried at 100 ° C. Got

(Synthesis Example 3) Synthesis of Urethane Urea Resin A-3 (Resin Acid Value 30 mgKOH / g)
Polyester polyol obtained from terephthalic acid, adipic acid and 3-methyl-1,5-pentanediol in a reaction vessel equipped with a stirrer, a thermometer, a reflux cooler, a dropping device, and a nitrogen introduction tube (manufactured by Kuraray Co., Ltd.) "Kurare Polyester P-2011", Mn = 2011) 160.2 parts, Dimethylol butanoic acid 19.39 parts, Isophorone diisocyanate 60.1 parts, Toluene 110 parts were charged and reacted at 90 ° C. for 3 hours under a nitrogen atmosphere. Toluene was added to 220 parts of toluene to obtain a urethane prepolymer solution having an isocyanate group. Next, a mixture of 1.72 parts of isophoronediamine, 0.17 parts of di-n-butylamine, 44 parts of 2-propanol and 68 parts of toluene was mixed with 534.7 parts of the obtained urethane prepolymer solution having an isocyanate group. A-3, a urethane urea resin having an acid value of 30 mgKOH / g and a weight average molecular weight of 57,000, was reacted at 50 ° C. for 3 hours and then at 70 ° C. for 2 hours, and then vacuum-dried at 100 ° C. Got

(Synthesis Example 4) Synthesis of Urethane Urea Resin A-4 (Resin Acid Value 50 mgKOH / g)
Polyester polyol obtained from terephthalic acid, adipic acid and 3-methyl-1,5-pentanediol in a reaction vessel equipped with a stirrer, a thermometer, a reflux cooler, a dropping device, and a nitrogen introduction tube (manufactured by Kuraray Co., Ltd.) "Kurare Polyester P-2011", Mn = 2011) 122.4 parts, dimethylol butanoic acid 32.32 parts, isophorone diisocyanate 80.1 parts, toluene 110 parts were charged and reacted at 90 ° C. for 3 hours under a nitrogen atmosphere. Toluene was added to 220 parts of toluene to obtain a urethane prepolymer solution having an isocyanate group. Next, a mixture of 1.88 parts of isophorondiamine, 0.19 parts of di-n-butylamine, 44 parts of 2-propanol and 68 parts of toluene was mixed with 534.7 parts of the obtained urethane prepolymer solution having an isocyanate group. A-4, which is a urethane urea resin having an acid value of 50 mgKOH / g and a weight average molecular weight of 57,500, is subjected to vacuum drying at 100 ° C. after a reaction at 50 ° C. for 3 hours and then at 70 ° C. for 2 hours. Got

(Synthesis Example 5) Synthesis of Urethane Urea Resin A-5 (Resin Acid Value 100 mgKOH / g)
Polyester polyol (manufactured by Kuraray Co., Ltd.) obtained from terephthalic acid, adipic acid and 3-methyl-1,5-pentanediol in a reaction vessel equipped with a stirrer, a thermometer, a reflux cooler, a dropping device, and a nitrogen introduction tube. "Kurare Polyol P-2011", Mn = 2011) 28.0 parts, dimethylol butanoic acid 64.64 parts, isophorone diisocyanate 130.0 parts, toluene 110 parts were charged and reacted at 90 ° C. for 3 hours under a nitrogen atmosphere. Toluene was added to 220 parts of toluene to obtain a urethane prepolymer solution having an isocyanate group. Next, a mixture of 1.52 parts of isophoronediamine, 0.15 parts of di-n-butylamine, 44 parts of 2-propanol and 68 parts of toluene was mixed with 534.7 parts of the obtained urethane prepolymer solution having an isocyanate group. A-5, a urethane urea resin having an acid value of 100 mgKOH / g and a weight average molecular weight of 58,000, is subjected to vacuum drying at 100 ° C. after reacting at 50 ° C. for 3 hours and then at 70 ° C. for 2 hours. Got

(Synthesis Example 6) Synthesis of Polyamide Resin A-6 (Resin Acid Value 13 mgKOH / g)
In a 4-necked flask equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, an introduction tube, and a thermometer, 156.2 g of prepol 1009 as a polybasic acid compound, 5.5 g of 5-hydroxyisophthalic acid, and preamine as a polyamine compound. 146.4 g of 1074 and 100 g of ion-exchanged water were charged, and the mixture was stirred until the heat generation temperature became constant. When the temperature became stable, the temperature was raised to 110 ° C, and after confirming the outflow of water, the temperature was raised to 120 ° C 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C every 30 minutes. .. When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant was added to obtain a polyamide resin A-6 having an acid value of 13 mgKOH / g, a weight average molecular weight of 24,000, a hydroxyl value of 5.5 mgKOH / g, and a glass transition temperature of 32 ° C.

(Synthesis Example 7) Synthesis of Urethane Urea Resin A-7 (Resin Acid Value 5 mgKOH / g)
Polyester polyol (manufactured by Kuraray Co., Ltd.) obtained from terephthalic acid, adipic acid and 3-methyl-1,5-pentanediol in a reaction vessel equipped with a stirrer, a thermometer, a reflux cooler, a dropping device, and a nitrogen introduction tube. "Kurare Polyol P-2011", Mn = 2011) 207.5 parts, dimethylol butanoic acid 3.23 parts, isophorone diisocyanate 35.2 parts, and toluene 110 parts were charged and reacted at 90 ° C. for 3 hours under a nitrogen atmosphere. 220 parts of toluene was added to obtain a urethane prepolymer solution having an isocyanate group. Next, a mixture of 1.59 parts of isophoronediamine, 0.16 parts of di-n-butylamine, 44 parts of 2-propanol and 68 parts of toluene was mixed with 534.7 parts of the obtained urethane prepolymer solution having an isocyanate group. A-7, a urethane urea resin having an acid value of 5 mgKOH / g and a weight average molecular weight of 61,500, was reacted at 50 ° C. for 3 hours and then at 70 ° C. for 2 hours, and then vacuum-dried at 100 ° C. Got

<Synthesis of boron-containing carbon (B)>
(Synthesis Example 8) Synthesis of B-1 The mass ratio of flaky graphite UP-20 (manufactured by Nippon Graphite Industry Co., Ltd.) and boric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) is 95/5 (graphite / boric acid). Weighed in the same manner as described above and mixed in a dairy pot to obtain a mixture. The above mixture was filled in a graphite crucible and heat-treated at 2100 ° C. for 1 hour in an argon atmosphere in a multipurpose high temperature furnace to obtain a boron-containing carbon material (B-1).

(Synthesis Example 9) Synthesis of B-2 Spheroidized graphite CGB-50 (manufactured by Nippon Graphite Industry Co., Ltd.) and boric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) have a mass ratio of 84/16 (graphite / boric acid). Weighed in the same manner as described above and mixed in a mortar to obtain a mixture. The above mixture was filled in a graphite crucible and heat-treated at 2200 ° C. for 1 hour in an argon atmosphere in a multipurpose high temperature furnace to obtain a boron-containing carbon material (B-2).

(Synthesis Example 10) Synthesis of B-3 Scale graphite F # 1 (manufactured by Nippon Graphite Industry Co., Ltd.) and boric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) have a mass ratio of 80/20 (graphite / boric acid). Weighed in each and mixed in a mortar to obtain a mixture. The above mixture was filled in a graphite crucible and heat-treated at 2200 ° C. for 1 hour in an argon atmosphere in a multipurpose high temperature furnace to obtain a boron-containing carbon material (B-3).

(Synthesis Example 11) B-4 synthesis Ketjen Black EC-300J (manufactured by Lion Specialty Chemicals, specific surface area 800 m ² / g) and boric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.), mass ratio 95/5 Weighed so as to be (Ketchen black / boric acid) and mixed in a dairy pot to obtain a mixture. The above mixture was filled in a graphite crucible and heat-treated at 2200 ° C. for 1 hour in an argon atmosphere in a multipurpose high-temperature furnace to obtain a boron-containing carbon material (B-4, specific surface area 127 m ² / g).

(Synthetic Example 12) Synthesis of B-5 Ketjen Black EC-300J (manufactured by Lion Specialty Chemicals) and boric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) have a mass ratio of 90/10 (Ketchen Black / boric acid). ), And mixed in a mortar to obtain a mixture. The above mixture was filled in a graphite crucible and heat-treated at 2200 ° C. for 1 hour in an argon atmosphere in a multipurpose high-temperature furnace to obtain a boron-containing carbon material (B-5, specific surface area 123 m ² / g).

(Synthesis Example 13) B-6 synthesis Ketjen Black EC-300J (manufactured by Lion Specialty Chemicals) and boric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) have a mass ratio of 70/30 (Ketchen Black / boric acid). ), And mixed in a mortar to obtain a mixture. The above mixture was filled in a graphite crucible and heat-treated at 2200 ° C. for 1 hour in an argon atmosphere in a multipurpose high temperature furnace to obtain a boron-containing carbon material (B-6, specific surface area 120 m ² / g).

(Synthesis Example 14) Synthesis of B-7 Multi-walled carbon nanotube 100P (manufactured by Knano, specific surface area 200 m ² / g) and boric acid (manufactured by Fuji Film Wako Junyaku Co., Ltd.) with a mass ratio of 80/20 (carbon nanotube / hoe). Weighed so as to be (acid), and mixed in a dairy pot to obtain a mixture. The above mixture was filled in a graphite crucible and heat-treated at 2200 ° C. for 1 hour in an argon atmosphere in a multipurpose high temperature furnace to obtain a boron-containing carbon material (B-7, specific surface area 137 m ² / g).

(Synthesis Example 15) Synthesis of B-8 Graphene nanoplatelet C-750 (manufactured by XG Sciences, specific surface area 700 m ² / g) and boric acid (manufactured by Fuji Film Wako Junyaku Co., Ltd.) have a mass ratio of 50/50 (graphene). Weighed so as to be nanoplatelets / boric acid) and mixed in a dairy pot to obtain a mixture. The above mixture was filled in a graphite crucible and heat-treated at 2200 ° C. for 1 hour in an argon atmosphere in a multipurpose high temperature furnace to obtain a boron-containing carbon material (B-8, specific surface area of 165 m ² / g).

(Synthesis Example 16) Synthesis of B-9 Flake graphite UP-20 (manufactured by Nippon Graphite Industry Co., Ltd.) and boric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) have a mass ratio of 75/25 (graphite / boric acid). Each was weighed in such a manner and mixed in a dairy pot to obtain a mixture. The above mixture was filled in a graphite crucible and heat-treated at 2200 ° C. for 1 hour in an argon atmosphere in a multipurpose high temperature furnace to obtain a boron-containing carbon material (B-9).

(Synthesis Example 17) B-4A synthesis Ketjen Black EC-600JD (manufactured by Lion Specialty Chemicals, specific surface area 1270 m ² / g) and boric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.), mass ratio 95/5 Weighed so as to be (Ketchen black / boric acid) and mixed in a dairy pot to obtain a mixture. The above mixture was filled in a graphite crucible and heat-treated at 2200 ° C. for 1 hour in an argon atmosphere in a multipurpose high temperature furnace to obtain a boron-containing carbon material (B-4A, specific surface area 261 m ² / g).

Table 1 shows the G / D ratio, specific surface area, and boron element content of the obtained boron-containing carbon material.

<Manufacturing of conductive material composition>
[Example 1]
(Dispersion 1)
8.0 parts of A-1 as a binder resin, 16.0 parts of B-1 as a boron-containing carbon material, 4.0 parts of B-4, a mixed solvent of toluene and isopropyl alcohol (IPA) (mass ratio 1: 1). 1) 52.0 parts of each were weighed and mixed. Further, 140 parts of zirconia beads (φ1.25 mm) were added, and the mixture was shaken with Scandex for 2 hours and then filtered to remove the zirconia beads to obtain a dispersion liquid 1 as a conductive material composition.

[Examples 2 to 25, 2A, 2B, 2C, 11A, 11B]
(Dispersions 2 to 25, 2A, 2B, 2C, 11A, 11B)
Dispersion liquids 2 to 25, 2A, 2B, and 2C were obtained in the same manner as in the dispersion liquid 1 except that the constituent components and their contents were changed to the contents shown in Tables 2 to 4.
In Examples 11A and 11B, the constituent components and their contents were changed to the contents shown in Table 2, and the shaking time in Scandex was changed to 6 hours, but the dispersion was carried out in the same manner as in the dispersion liquid 1. Liquids 11A and 11B were obtained.

[Comparative Examples 1 to 6]
(Dispersions 101 to 106)
Dispersions 101 to 106 were obtained in the same manner as in the dispersion 1 except that the constituents and their contents were changed to the contents shown in Tables 2 to 4.

<Evaluation of conductive composition>
The obtained conductive composition was evaluated as follows. The results are shown in Tables 2-4.

(Dispersion stability)
The dispersion stability of the conductive composition was evaluated from the rate of change in viscosity over time in the dispersion viscosity test.
⊚: Viscosity change rate at constant temperature at 40 ° C for 1 week is less than 5% (very good)
〇: Viscosity change rate at constant temperature at 40 ° C for 1 week is 5% or more and less than 10% (good)
Δ: Constant temperature viscosity change rate at 40 ° C. for 1 week is 10% or more and less than 20% (usable)
×: Viscosity change rate at constant temperature at 40 ° C for 1 week is 20% or more (cannot be used)

(Initial dispersion viscosity)
The initial viscosity of the conductive composition was measured using a B-type viscometer (TVB10 type manufactured by Toki Sangyo Co., Ltd.) in an environment of 25 ° C.
⊚: Initial viscosity is less than 300 mPa · s (very good)
〇: Initial viscosity is 300 mPa · s or more and less than 3,000 mPa · s (good)
Δ: Initial viscosity is 3,000 mPa · s or more and less than 6,000 mPa · s (usable)
×: Initial viscosity is 6,000 mPa · s or more (cannot be used)

(Resin adsorptive)
The amount of adsorbed binder resin in the conductive composition is determined by separating the dispersion liquid with a centrifuge (50,000 rpm, 3 hours), separating the supernatant, separating a small amount of the separated supernatant, and using a dryer. It was calculated from the amount of residual solid content obtained by volatilizing the solvent content.
⊚: Resin adsorption amount is less than 15% (very good)
〇: Resin adsorption amount is 15% or more and less than 20% (good)
Δ: Resin adsorption amount is 20% or more and less than 30% (usable)
×: Resin adsorption amount is 30% or more (cannot be used)

(Initial dispersion viscosity)
The initial viscosity of the conductive composition was measured using a B-type viscometer (TVB10 type manufactured by Toki Sangyo Co., Ltd.) in an environment of 25 ° C.
⊚: Initial viscosity is less than 300 mPa · s (very good)
〇: Initial viscosity is 300 mPa · s or more and less than 3,000 mPa · s (good)
Δ: Initial viscosity is 3,000 mPa · s or more and less than 6,000 mPa · s (usable)
×: Initial viscosity is 6,000 mPa · s or more (cannot be used)

(Aptitude for coating)
The coating suitability of the conductive composition was evaluated using a grind gauge (groove depth 50 μm).
⊚: No streaks or coarse particles due to coarse particles of 10 μm or more (very good)
〇: There are streaks and coarse particles due to coarse particles of 10 μm or more, but there are no streaks or coarse particles due to coarse particles of 20 μm or more (good).
Δ: There are streaks and coarse particles due to coarse particles of 20 μm or more, but there are no streaks or coarse particles due to coarse particles of 30 μm or more (usable).
×: There are streaks and coarse particles due to coarse particles of 30 μm or more (cannot be used).

<Evaluation of coating film (conductive film)>
The obtained conductive composition was applied to a PET film having a thickness of 100 μm, which is a sheet-like substrate, using an applicator, and then heated and dried at 120 ° C. for 30 minutes to form a film thickness on the PET substrate. A laminate having a conductive film of 20 μm was obtained. Using the obtained laminate, the conductivity (conductivity), durability, and smoothness were evaluated as follows.

(Conductivity of conductive film)
The volume resistivity of the conductive film was measured by the 4-terminal method (JIS-K7194) using Loresta GP (manufactured by Mitsubishi Chemical Analytech Co., Ltd.), and was determined according to the following criteria.
◎ ◎: Volume resistivity is less than 2 × 10 ^-3 Ω ・ cm (extremely good)
⊚: Volume resistivity is 2 × 10 ^-3 Ω ・ cm or more and less than 3 × 10 ^-3 Ω ・ cm (very good)
◯: Volume resistivity is 3 × 10 ^-3 Ω ・ cm or more and less than 5 × 10 ^-3 Ω ・ cm (good)
○ △: Volume resistivity is 5 × 10 ^-3 Ω ・ cm or more, 7 × 10 ^-3 Ω ・ cm or less (usable)
Δ: Volume resistivity is 7 × 10 ^-3 Ω ・ cm or more and less than 1 × 10 ^-2 Ω ・ cm (defective)
×: Volume resistivity is 1 × 10 ^-2 Ω · cm or more (extremely defective)

(Durability of conductive film)
The durability of the conductive film was evaluated by scratch hardness (pencil method) using a pencil having a hardness of HB (JIS K5600-5-4: 1999 method compliant).
⊚: No plastic deformation or cohesive fracture occurs even after 10 tests (very good)
〇: No plastic deformation or cohesive fracture occurs in two evaluations (good)
Δ: Plastic deformation or cohesive fracture occurred in two evaluations (usable)
×: Plastic deformation and cohesive fracture occurred in two evaluations (cannot be used)

(Coarse grain state of conductive film)
The surface of the conductive film was visually observed and evaluated using a scanning electron microscope (SEM).
⊚: No coarse particles are seen (very good)
〇: The total area of coarse particles is 5% or less of the display range (good)
Δ: The total area of coarse particles is 5% or more and 10% or less with respect to the display range (usable).
X: The total area of coarse particles is 10% or more of the display range (cannot be used).

The abbreviations listed in Tables 2-4 are shown below.
-UP-20: Thinned graphite UP-20 (manufactured by Nippon Graphite Industry Co., Ltd.)
-EC-300J: Ketjen Black EC-300J (manufactured by Lion Specialty Chemicals)
-NMP: N-methylpyrrolidone-100T: Carbon nanotube 100T (manufactured by Knano)

As shown in Tables 2 to 4, the conductive composition of the present invention had a low initial viscosity and showed excellent dispersibility and coatability. Further, the conductive film formed from the composition was excellent in conductivity and smoothness. Further, the conductive composition of the present invention had a low amount of resin adsorbed, and the conductive film formed from the composition showed excellent durability.
According to Table 2, in particular, when the acid value of the binder resin (A) is in the range of 10 to 60 mgKOH / g, a conductive film that does not inhibit the formation of a conductive network and has excellent film strength is formed. Therefore, the conductivity (conductivity) and the durability of the conductive film were excellent. Above all, when the acid value was in the range of 10 to 40 mgKOH / g, the coating suitability was excellent in addition to the conductivity and the durability of the conductive film.
Further, Examples 11A and 11B in which carbon nanotubes were used as the carbon material of the boron-containing carbon had excellent conductivity.
Further, when a boron-containing carbon material using Ketjen black having a large specific surface area was used, the conductivity was improved by reducing the ratio (Examples 2A and 2C).

According to Table 3, in the composition using Ketjen Black as the carbon material of the boron-containing carbon material, the dispersion stability and the initial dispersion viscosity were improved by reducing the blending amount of Ketjen Black.
According to Table 4, the composition using carbon nanotubes as the carbon material of the boron-containing carbon material was particularly excellent in the conductivity and smoothness of the conductive film.

On the other hand, in Comparative Example 1 using a tree binder resin having a low acid value, it was confirmed that the durability and the conductivity were lowered. Further, in Comparative Example 2 using a carbon material containing no boron, dispersibility and coatability deteriorated, and conductivity and durability were also inferior.

Claims (9)

A conductive composition containing a binder resin (A) having an acid value of 10 mgKOH / g or more and a boron-containing carbon material (B). The conductive composition according to claim 1, wherein the binder resin (A) has an acid value of 10 to 100 mgKOH / g. The conductive composition according to claim 1 or 2, wherein the boron-containing carbon material (B) has a boron element content of 0.001 to 15 mol%. The conductive composition according to any one of claims 1 to 3, wherein the binder resin (A) contains at least one selected from the group consisting of polyurethane, polyamide and polyester. The conductive composition according to any one of claims 1 to 4, wherein the mass ratio of the solid content of the binder resin (A) to the boron-containing carbon material (B) is 5:95 to 95: 5. The conductive composition according to any one of claims 1 to 5, wherein the carbon material in the boron-containing carbon material (B) contains at least one selected from the group consisting of graphite, carbon nanotubes, graphene nanoplatelets and graphene. thing. The carbon material in the boron-containing carbon material (B) is graphite, and the boron-containing carbon material (B) has a D band (1330-1370 cm ^-1 ) and a G band (1560-1620 cm) in a laser Raman spectrum having an excitation laser wavelength of 532 nm. ^-1 ) The conductive composition according to any one of claims 1 to 6, wherein the [G / D] ratio, which is the ratio (IG / ID) of the peak intensity to 1), is 1.0 or more. The carbon material in the boron-containing carbon material (B) is carbon black, graphene nanoplatelets or graphene, and the boron-containing carbon material (B) is a D band (1330-1370 cm ^-1 ) in a laser Raman spectrum having an excitation laser wavelength of 532 nm. ) And the [G / D] ratio, which is the ratio (IG / ID) of the peak intensity to the G band (1560-1620 cm ^-1 ), is 0.5 or more, according to any one of claims 1 to 6. Conductive composition. A conductive film formed from the conductive composition according to any one of claims 1 to 8.