JP2019110108A - Conductive composition, and conductive film - Google Patents

Abstract

To provide a conductive composition having excellent conductivity, the conductive composition having specifically excellent conductivity and adhesion by setting a mixture ratio of a binder resin and a conductive carbon material and setting a mixture ratio of graphite as the conductive carbon material and carbon other than graphite in specific ranges, and a conductive film.SOLUTION: A conductive composition contains a binder resin (A) and a carbon material (B). The carbon material (B) contains graphite (B-1) and a carbon material other than graphite (B-2). A mass ratio between a solid content of the binder resin (A) and the carbon material (B) is 15:85-35:65. The graphite (B-1) content is 75.0-99.0 mass% in the carbon material (B) 100 mass%.SELECTED DRAWING: None

Description

  The present invention relates to a conductive composition containing a binder resin and a carbon material.

  In recent years, the development of electronics has been remarkable, and the conductive materials used in various electronic devices are also required to be smaller in size, lighter in weight, lower in cost, and longer in life in various usage environments. It is coming. For example, in the case of producing a wiring for connecting a substrate wiring of an electronic device or an electronic device, a conductive composition having good conductivity is required, but a conductive composition using a metal filler such as silver or copper is generally used. And the big problem is not yet solved in the point of cost. On the other hand, various studies have been conducted on conductive compositions using conductive carbon which does not use metals, but since the conductivity is insufficient, it is limited to use in semiconductive applications such as antistatic applications. The

Further, as conductive carbon materials, various conductive materials having low volume resistivity, such as various graphites and carbon nanotubes, have been studied to date. The volume resistivity of these conductive carbon materials is as high as less than 10 ^-2 Ω · cm, but many carbon materials with excellent conductivity have large specific surface area, and they are uniform in resin and solvent. Sometimes it is difficult to mix and disperse, and a defect occurs in the contact between carbon materials in a coating film or a molded product obtained from a conductive composition containing a conductive carbon material, a resin, a solvent, etc. There is a problem that the conductivity can not be sufficiently expressed (Patent Documents 1 to 3).
Thus, Patent Documents 4 to 18 disclose conductive compositions in which graphite and carbon black are used in combination in a binder in order to develop a conductive network between carbon materials in a coating.

  Patent Documents 17 and 18 disclose the correlation between the mixing ratio of resin and conductive carbon material, the mixing ratio of graphite and carbon black, and the conductivity. Depending on the mixing ratio of the resin and the conductive carbon material, and the mixing ratio of the graphite and the carbon black, the contact state between the carbon materials in the coating film and the molded product changes, and the conductivity reaches a maximum value under predetermined conditions. Although indicated, the study conditions were broad and discrete and not exhaustive.

Patent Documents 19 and 20 also disclose a conductive composition in which carbon fibers and carbon nanotubes are used in combination. Although the improvement of the conductivity by strengthening the conductive network was observed, there is still room for improvement in the dispersibility of the conductive carbon material in the resin and the solvent, and the volume resistivity of the coating film is also on the order of 10 ^-2 Ω · cm It often stayed in

  Therefore, in order to improve the dispersibility, in Patent Document 21, the change of the dispersion method is used, in Patent Documents 22 and 23, the use of the dispersant of the organic solvent composition is used, and in Patent Documents 24 and 25, the aqueous dispersion in the water based composition The use of agents is disclosed. However, although the dispersibility is improved, there is a problem that the conductivity is lowered by adding a dispersant which is an insulating material or damaging the conductive carbon material by miniaturization.

Unexamined-Japanese-Patent No. 3-7740 JP, 2001-60413, A JP 2002-20515 A JP-A-54-36343 Japanese Patent Application Laid-Open No. 62-88260 Japanese Patent Application Laid-Open No. 62-88261 Japanese Patent Application Laid-Open No. 62-199663 Japanese Patent Application Laid-Open No. 63-125580 JP-A 64-56777 Unexamined-Japanese-Patent No. 1-101373 Unexamined-Japanese-Patent No. 1-184901 Japanese Patent Application Laid-Open No. 2-284968 Unexamined-Japanese-Patent No. 5-65366 Japanese Patent Application Laid-Open No. 7-33883 Japanese Patent Application Laid-Open No. 7-41609 Japanese Patent Application Laid-Open No. 7-53813 JP 2001-102010 A Unexamined-Japanese-Patent No. 2003-238881 Unexamined-Japanese-Patent No. 6-122785 Unexamined-Japanese-Patent No. 2004-221071 JP-A-2-204317 JP 2001-254013 A JP, 2013-119577, A JP 2004-10705 A JP, 2015-128006, A

  An object of the present invention is a conductive composition excellent in conductivity, in which the mixing ratio of a binder resin and a carbon material, and the mixing ratio of graphite and carbon other than graphite as a carbon material are in a specific range. It is providing a conductive composition and a conductive film which are specifically excellent in conductivity and adhesiveness.

That is, the present invention is a conductive composition containing a binder resin (A) and a carbon material (B),
The carbon material (B) contains graphite (B-1) and a carbon material (B-2) other than graphite,
The mass ratio of the solid content of the binder resin (A) to the carbon material (B) is 15: 85 to 35: 65,
The conductive composition is characterized in that the content of the graphite (B-1) is 75.0 to 99.0 mass% in 100 mass% of the carbon material (B).

Further, the present invention relates to the above conductive composition characterized in that the content of the graphite (B-1) is 80.0 to 99.0 mass% in 100 mass% of the carbon material (B). .

Further, the present invention relates to the above conductive composition characterized in that the content of the graphite (B-1) is 90.0 to 97.5 mass% in 100 mass% of the carbon material (B). .

Further, the present invention relates to the above conductive composition characterized in that the mass ratio of the solid content of the binder resin (A) to the carbon material (B) is 20:80 to 30:70.

The conductive composition as described above, wherein the binder resin (A) comprises a polyurethane, a polyamide, or a polyester.

The present invention also relates to the above-mentioned conductive composition, wherein the carbon material (B-2) other than graphite contains carbon black.

The present invention also relates to a conductive film obtained by using the above-mentioned conductive composition.

  In a conductive composition containing a binder resin (A) and a conductive carbon material (B), a mixture ratio of the binder resin and the conductive carbon material, and a mixture of carbon and carbon other than graphite as the conductive carbon material When the ratio is in the specific range, the carbon materials in the conductive film formed of the conductive composition have good contact and binding properties with each other, so that an excellent conductive network is formed and the conductivity is excellent. A conductive film can be provided.

<Conductive composition>
The conductive composition of the present invention contains a binder resin (A), a carbon material (B), and, if necessary, a solvent.

  Moreover, although the appropriate viscosity of the conductive composition depends on the coating method of the conductive composition, it is generally preferable to be 10 mPa · s or more and 30,000 mPa · s or less.

  First, the binder resin (A) will be described.

The binder resin is selected from the group consisting of polyurethane, polyamide, acrylonitrile, acrylic, butadiene, polyvinyl butyral, polyolefin, polyester, polystyrene, EVA, polyvinylidene fluoride, silicone resin, etc. It can contain one or more. In particular, polyurethanes, polyamides and polyesters are preferred. However, it is not necessarily limited to these resins. The binder resin may be used alone or in combination of two or more.
The binder resin can also be a curable resin that undergoes a curing (crosslinking) reaction after the binder resin is applied to the substrate.
That is, the binder resin is selected (self-curable) or combined with a curing agent to be described later, and then the conductive composition is printed or coated on the substrate and then cured (crosslinked). You can also.

The binder resin is preferably a polyurethane resin from the viewpoint of volume resistivity, adhesion to a substrate, and durability. After printing or coating the conductive composition on a substrate, when (hot) pressing is performed, the resin component is softened and substantially maintains the planar pattern shape of the conductive film at the time of printing and coating. However, when it flows in the thickness direction, it is possible to reduce the voids and increase the contact between the conductive carbon materials (B), and therefore, it is possible to expect a decrease in the volume resistivity of the obtained conductive film. Therefore, as the binder resin, one that softens and flows appropriately during (heat) pressing is preferable.

<Polyurethane resin>
The synthesis method of the polyurethane resin is not particularly limited. For example, the polyol compound (a) and the diisocyanate (b) are reacted, or the polyol compound (a), the diisocyanate (b) and the diol compound having a carboxyl group (c) With an isocyanate group, obtain a urethane prepolymer (d) having an isocyanate group, further react the polyamino compound (e) with the urethane prepolymer (d), or react as necessary in the above three cases. What is obtained by making a terminator react is mentioned.

As a polyol compound (a), various polyether polyols generally known as a polyol component which comprises a polyurethane resin, polyester polyols, polycarbonate polyols, polybutadiene glycols, or these mixtures etc. can be used.

Examples of polyether polyols include polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran and the like.
As polyester polyols, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1, Saturated and unsaturated low molecular weight diols such as 5-pentanediol, hexanediol, octanediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, dimer diol, and n-butyl glycidyl ether, 2 -Monocarboxylic acid glycidyl esters such as alkyl glycidyl ethers of ethyl hexyl glycidyl ethers, glycidyl esters of versatic acid, and adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid Polyester polyols obtained by dehydrating condensation of dicarboxylic acids such as fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, or their anhydrides, Polyester polyols obtained by ring-opening polymerization of cyclic ester compounds may be mentioned.
As polycarbonate polyols, 1) a reaction product of a diol or bisphenol and a carbonic ester, and 2) a reaction product of a diol or a bisphenol with phosgene in the presence of an alkali can be used. Examples of carbonates include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, propylene carbonate and the like. Further, as the diol, ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol, 3,3 '-Dimethylolheptane, polyoxyethylene glycol, polyoxypropylene glycol, propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9 Nonanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, 3,9-bis (1,1-dimethyl-2-hydroxyethyl, 2,2 , 8, 10-Tetraoxo spiro [5.5]
Undecane etc. are mentioned. Examples of bisphenols include bisphenol A and bisphenol F, and bisphenols obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to bisphenols.

The number average molecular weight (Mn) of the polyol compound is appropriately determined in consideration of the solubility of the polyurethane resin when producing the conductive composition, the durability of the conductive film to be formed, the adhesive strength to the substrate, and the like. However, in general, the range of 580 to 8000 is preferable, and more preferably 1000 to 5000.
The above-mentioned polyol compounds may be used alone or in combination of two or more. Furthermore, within the range where the performance of the polyurethane resin is not lost, part of the above-mentioned polyol compound can be replaced by low molecular weight diols, for example, various low molecular weight diols used for the production of the above-mentioned polyol compound.

As the diisocyanate compound (b), aromatic diisocyanate, aliphatic diisocyanate, alicyclic isocyanate, or a mixture thereof can be used, and isophorone diisocyanate is particularly preferable. As aromatic diisocyanates, 1,5-naphthyl diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-benzylisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1 And 3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate and the like.

Examples of aliphatic diisocyanates include butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate.
Examples of alicyclic diisocyanates include cyclohexane-1,4-diisocyanate, isophorone diisocyanate, norbornane diisocyanate methyl, bis (4-isocyanatocyclohexyl) methane, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate and the like. Be

Examples of the diol compound (c) having a carboxyl group include dimethylolalkanoic acid such as dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid and dimethylolpentanoic acid, dihydroxysuccinic acid and dihydroxybenzoic acid. In particular, dimethylol propionic acid and dimethylol butanoic acid are preferable in terms of reactivity and solubility.
The conditions for obtaining the urethane prepolymer (d) having an isocyanate group by reacting the polyol compound (a), the diisocyanate (b) and the diol compound (c) having a carboxyl group are: There is no particular limitation, but it is preferable that the equivalent ratio of isocyanate group / hydroxyl group is 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 at a temperature between normal temperature and 150 ° C., and is further carried out preferably at a temperature of 60 ° C. to 120 ° C. in terms of production time and control of side reactions.

The polyamino compound (e) works as a chain extender, and in addition to ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine and norbornanediamine, 2 Using amines having a hydroxyl group, such as-(2-aminoethylamino) ethanol, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxypropylethylenediamine, etc. it can. Among them, isophorone diamine is preferably used.

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

Conditions for reacting the urethane prepolymer (d) having an isocyanate group, the polyamino compound (e), and, if necessary, the reaction terminator are not particularly limited, but free isocyanate having at both ends of the urethane prepolymer When the group is one equivalent, 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.

At the time of synthesis of the polyurethane resin, one or two selected from ester solvents, ketone solvents, glycol ether solvents, aliphatic solvents, aromatic solvents, alcohol solvents, carbonate solvents, water and the like alone or The above can be used in combination.
Examples of ester solvents include ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, ethyl lactate and the like.
Examples of the ketone-based solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone benzene, diisobutyl ketone, diacetone alcohol, isophorone, cyclohexanenon and the like.
Examples of glycol ether 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 include glycol monomethyl ether, propylene glycol monoethyl ether, and acetic acid esters of these monoethers.
Examples of aliphatic solvents include n-heptane, n-hexane, cyclohexane, methylcyclohexane, ethylcyclohexane and the like.
Examples of the aromatic solvents include toluene and xylene.
Examples of alcohol solvents include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, cyclohexanol and the like.
Examples of carbonate solvents include dimethyl carbonate, ethyl methyl carbonate, di-n-butyl carbonate and the like.

<Polyamide resin>
The binder resin is preferably a polyamide resin from the viewpoint of volume resistivity and adhesion to a substrate. The volume resistivity gives a good result because the resin component in the (hot) press tends to flow.
The polyamide resin used in the present invention is a general term for a polymer having an amide bond which is basically obtained by various reactions such as polycondensation of dibasic acid and diamine, polycondensation of aminocarboxylic acid, or ring-opening polymerization of lactam. And various modified polyamides, products produced by partially hydrogenated reaction products, products obtained by partially copolymerizing other monomers, or other materials such as various additives. It is a broad concept that includes things and so on.

The polyamide resin used in the present invention is not particularly limited as long as the above conditions are satisfied, but a dimer acid-modified polyamide resin obtained by condensation polymerization of a dibasic acid composed mainly of a dimer acid and a polyamine is preferable. . A dimer acid obtained by polymerizing a natural monobasic unsaturated fatty acid contained in tall oil fatty acid, soybean oil fatty acid and the like is widely used industrially as a dimer acid when producing a dimer acid-modified polyamide resin. May be various dicarboxylic acids such as saturated aliphatic, unsaturated aliphatic, alicyclic or aromatic.
Examples of commercial products of the dimer acid include Halidimers 200 and 300 (manufactured by Harima Chemicals, Inc.), Versadimes 228 and 216, and Empoles 1018, 1019, 1061 and 1062 (manufactured by Kogniss). Furthermore, hydrogenated dimer acids can also be used, and commercially available hydrogenated dimer acids include Pripol 1009 (manufactured by Croda Japan Co., Ltd.) and Empol 1008 (manufactured by Cognis).
In addition to the above-mentioned dimer acid, various dicarboxylic acids can be used as a dibasic acid in order to obtain a polyamide resin having appropriate flexibility. Specific examples of the dicarboxylic acid include oxalic acid, malonic acid, (anhydride) succinic acid, (anhydride) maleic acid, glutaric acid, adipic acid, bimelic acid, suberic acid, azelaic acid, sebacic acid, terephthalic acid and isophthalic acid. An acid, phthalic acid, naphthalene dicarboxylic acid, 1,3- or 1,4-cyclohexanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid or the like is used.

Furthermore, those having a phenolic hydroxyl group can also be used as a dibasic acid. By using a dibasic acid having a phenolic hydroxyl group, a phenolic hydroxyl group can be introduced into the side chain of the polyamide resin, and can be used for the reaction with a curing agent.
Examples of dibasic acids having a phenolic hydroxyl group include hydroxyisophthalic acids such as 2-hydroxyisophthalic acid, 4-hydroxyisophthalic acid and 5-hydroxyisophthalic acid, 2,5-dihydroxyisophthalic acid, 2,4-dihydroxyisophthalic acid, Dihydroxyisophthalic acid such as 4,6-dihydroxyisophthalic acid, 2-hydroxyterephthalic acid, 2,3-dihydroxyterephthalic acid, dihydroxyterephthalic acid such as 2,6-dihydroxyterephthalic acid, 4-hydroxyphthalic acid, 3-hydroxyphthalic acid Examples thereof include hydroxyphthalic acid such as acid, 3,4-dihydroxyphthalic acid, 3,5-dihydroxyphthalic acid, 4,5-dihydroxyphthalic acid, and dihydroxyphthalic acid such as 3,6-dihydroxyphthalic acid.
Further, these acid anhydrides and ester derivatives such as polybasic acid methyl ester may also be mentioned.
Among them, 5-hydroxyisophthalic acid is preferable in terms of copolymerizability, availability, and the like.

Furthermore, various monocarboxylic acids are used as needed to obtain a polyamide resin having appropriate fluidity when heated. Specific examples of the monocarboxylic acid include propionic acid, acetic acid, caprylic acid (octanoic acid), stearic acid, and oleic acid.
Examples of polyamines as reactants in the production of the dimer acid-modified polyamide resin include various diamines such as aliphatic, alicyclic and aromatic, triamines and polyamines. Specific examples of the above diamines include ethylenediamine, propanediamine, butanediamine, triethylenediamine, tetraethylenediamine, hexamethylenediamine, p- or m-xylenediamine, 4,4'-methylenebis (cyclohexylamine), 2,2-bis -(4-cyclohexylamine), polyglycol diamine, isophorone diamine, 1,2-, 1,3- or 1,4-cyclohexane diamine, 1,4-bis- (2'-aminoethyl) benzene, N-ethyl Amino piperazine, piperazine and the like.
Moreover, diethylene triamine etc. are mentioned as a triamine, Triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine etc. are mentioned as a polyamine. Furthermore, dimer diamines obtained by converting dimerized aliphatic nitrile groups and reducing them with hydrogen can also be used.

Moreover, as a polyamine compound, the compound which converted the carboxyl group of the polybasic acid compound which has a C20-C48 cyclic or non-cyclic hydrocarbon group into an amino group is mentioned, As an example of a commercial item, Croda is mentioned, for example Examples thereof include "Priamine 1071", "Priamine 1073", "Priamine 1074", and "Priamine 1075" manufactured by Japan, and "Bursamine 551" manufactured by Cognis Japan.
An alkanolamine may be used in combination with the diamine. The alkanolamines include ethanolamine, propanolamine, diethanolamine, butanolamine, 2-amino-2-methyl-1-propanol, 2- (2-aminoethoxy) ethanol and the like. In addition, polyether diamine having oxygen as a skeleton can be used. The polyether has the general formula H ₂ N-R ₁ - in _{(RO) n -R 2 -NH 2} ( wherein, n is 2~100, R _1, R ₂ in the 1 to 14 carbon atoms R is an alkyl group or an alicyclic hydrocarbon group, and R is a carbon number of 1 to
10 alkyl groups or alicyclic hydrocarbon groups. The alkyl group may be linear or branched. It can be represented by). Examples of this ether diamine include polyoxypropylene diamine and the like, and commercially available products include Jeffamines (manufactured by Sun Techno Chemical Co., Ltd.). Mention may also be made of bis- (3-aminopropyl) -polytetrahydrofuran.
The above-mentioned polyamines and dimer acid or various dicarboxylic acids are heat-condensed by a conventional method, and various polyamide resins including a dimer acid-modified polyamide resin are manufactured by the amidation process accompanied by dehydration. In general, the reaction temperature is about 100 to 300 ° C., and the reaction time is about 1 to 8 hours.

<Polyester resin>
The binder resin is preferably a polyester resin from the viewpoint of volume resistivity and adhesion to a substrate. The volume resistivity gives a good result because the resin component in the (hot) press tends to flow.
The polyester resin is a polymer composed of a polyvalent carboxylic acid and a polyvalent alcohol as monomers. A well-known thing can be employ | adopted for a polyester resin, and, specifically, it is preferable that a weight average molecular weight is 1000-100000 from the point of securing of the cohesive force of resin. Further, in view of adhesion, the glass transition temperature is preferably -10 ° C to 200 ° C.
Examples of the polyvalent carboxylic acid component constituting the polyester resin include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, unsaturated dicarboxylic acids, trivalent or higher carboxylic acids, and the like, and one or two or more of these are listed. You can select and use the above. On the other hand, as a polyhydric alcohol component which comprises polyester resin, aliphatic glycol, ether glycols, the polyalcohol more than trivalence etc. can be mentioned, 1 type or more can be selected and used out of these.
Commercial products of polyester resin include Byron (Toyobo Co., Ltd., "Byron" is a registered trademark), Polyester (Nippon Synthetic Chemical Industry Co., Ltd., "Polyester" is a registered trademark), Teslac (Hitachi Kasei Polymer Co., Ltd.) , “Teslac” is a registered trademark) and the like.

As a binder resin, at least one structure selected from polyether, polyester, polycarbonate, or polybutadiene having a functional group capable of reacting with an isocyanate group from the viewpoints of volume resistivity, adhesion to a substrate, and durability. It is also preferable to include a vinyl polymer (A1) having a side chain. The volume resistivity gives a good result because the resin component in the (hot) press tends to flow.

(Polymer (A1))
The polymer (A1) is a polyether having a functional group capable of reacting with an isocyanate group in the main chain of a vinyl-based copolymer obtained by polymerizing a monomer having an ethylenically unsaturated double bond. It refers to a polyether, polyester, polycarbonate or polybutadiene graft vinyl polymer in which at least one structure selected from polyester, polycarbonate or polybutadiene is introduced as a side chain.

Examples of the functional group capable of reacting with the isocyanate group include a hydroxyl group, an amino group, a carboxyl group, an epoxy group, an N-methylol group, an N-alkoxymethyl group and the like, but a hydroxyl group is preferable in terms of reactivity.
The method for introducing the side chain is not particularly limited, but, for example, a copolymer (f) of an unsaturated dibasic acid and another monomer having an ethylenically unsaturated double bond is synthesized, It is selected from polyethers, polyesters, polycarbonates, or polybutadienes having a carboxylic acid or carboxylic anhydride moiety of the copolymer (f), a functional group capable of reacting with a carboxyl group, and a functional group capable of reacting with an isocyanate group It can introduce | transduce by carrying out the condensation reaction of the functional group which can react with the carboxyl group of at least 1 sort (g).
In addition, when used for applications requiring higher toughness and durability, in order to obtain higher crosslinking density, it is possible to introduce a functional group capable of reacting with isocyanate directly into the vinyl polymer main chain. desirable. In that case, the polymer (A1) is an unsaturated dibasic acid (f1), a monomer (f2) other than (f1) having an isocyanate-reactive functional group and an ethylenically unsaturated double bond, and ethylene (F) of a monomer (f3) other than (f1) and (f2) having a heterocyclic unsaturated double bond, a functional group capable of reacting with a carboxyl group, and a functional group capable of reacting with an isocyanate group And at least one (g) selected from polyethers, polyesters, polycarbonates, or polybutadienes.
Examples of unsaturated dibasic acids (f1) that can be used for the synthesis of the copolymer (f) include maleic acid, maleic anhydride, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, crotonic acid, diphenylmethane-diphenyl -Gamma- ketocrotonic acid etc. are mentioned.
The unsaturated dibasic acid (f1) can be used alone or in combination of two or more depending on the required performance. The proportion of unsaturated dibasic acid (f1) in the monomer used as the raw material of the copolymer (f) is preferably 0.01 to 30% by weight, more preferably 0.05 to 10% by weight. is there.
As a monomer (f2) other than (f1) having a functional group capable of reacting with isocyanate and an ethylenically unsaturated double bond, a (meth) acrylic monomer having a functional group capable of reacting with an isocyanate group A vinyl monomer etc. can be used. Among them, (meth) acrylic monomers are preferable in terms of reactivity.
Examples of the functional group capable of reacting with the isocyanate group include a hydroxyl group, an amino group, a carboxyl group, an epoxy group, an N-methylol group, an N-alkoxymethyl group and the like, but a hydroxyl group is preferable in terms of reactivity.

As a (meth) acrylic monomer having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, Polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polytetramethylene glycol mono (meth) acrylate and the like can be mentioned.
Examples of (meth) acrylic monomers having an amino group include methylaminoethyl (meth) acrylate, ethylaminoethyl (meth) acrylate, butylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate and the like N, N-dialkylamino such as monoalkylaminoalkyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylamino (meth) acrylate, N, N-dibutylaminoethyl (meth) acrylate Alkyl (meth) acrylate etc. are mentioned.
As a (meth) acrylic-type monomer which has a carboxyl group, acrylic acid, methacrylic acid, etc. are mentioned.
As a (meth) acrylic-type monomer which has an epoxy group, glycidyl (meth) acrylate etc. are mentioned.
Examples of the (meth) acrylic monomer having an N-methylol group include N-methylol (meth) acrylamide and the like.
As a (meth) acrylic monomer having an N-alkoxymethyl group, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-butoxymethyl ( (Meth) acrylamide having an N-monoalkoxymethyl group such as meta) acrylamide, N, N-dimethylol (meth) acrylamide, N, N-di (methoxymethyl) (meth) acrylamide, N, N-di (ethoxymethyl) ) (Meth) acrylamide having N, N-dialkoxymethyl group such as (meth) acrylamide, N, N-di (propoxymethyl) (meth) acrylamide, N, N-di (butoxymethyl) (meth) acrylamide, etc. Can be mentioned.

Examples of vinyl monomers include hydroxystyrene and vinyl alcohol.
Monomers (f2) other than (f1) having a functional group capable of reacting with isocyanate and an ethylenically unsaturated double bond may be used alone or in combination of two or more depending on the required performance. it can. Further, the proportion of the monomer (f2) in the monomer to be the raw material of the copolymer (f) is preferably 0.01 to 50% by weight, more preferably 0.1 to 20% by weight, particularly preferably Is 0.1 to 10% by weight.

Examples of monomers (f3) other than (f1) and (f2) having an ethylenically unsaturated double bond include (meth) acrylic monomers, aromatic vinyl monomers, olefin hydrocarbon monomers And vinyl ether monomers can be used.
Examples of (meth) acrylic monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and stearyl (meth) acrylate Alkyl (meth) acrylate, benzyl (meth) acrylate, etc. are mentioned.
Examples of the aromatic vinyl monomer include styrene, methylstyrene and ethylstyrene.
Examples of the olefin hydrocarbon monomer include ethylene, propylene, butadiene, isobutylene, isoprene, 1,4-pentadiene and the like.
Examples of vinyl ether monomers include vinyl methyl ether.
Monomers other than (f1) and (f2) having an ethylenically unsaturated double bond can be used singly or as a mixture of two or more depending on the required performance.

The copolymer (f) can be obtained by a known method, for example, solution polymerization. As the solvent, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol methyl ether, diethylene glycol methyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, etc. Ethers, hydrocarbons such as hexane, heptane and octane, aromatics such as benzene, toluene, xylene and cumene, and esters such as ethyl acetate and butyl acetate can be used. The solvents may be used as a mixture of two or more.
The feed concentration of the monomer at the time of synthesis is preferably 0 to 80% by weight.
As a polymerization initiator, peroxides or azo compounds such as benzoyl peroxide, azoisobutylvaleronitrile, azobisisobutyronitrile, di-t-butyl peroxide, t-butyl perbenzoate, t-butyl peroctoate, Cumene hydroxyperoxide and the like can be used, and the polymerization temperature is preferably 50 to 200 ° C, particularly 70 to 140 ° C.

The polystyrene equivalent weight average molecular weight of the copolymer (f) is preferably 5,000 to 500,000, more preferably 10,000 to 100,000.

The compound (g) is, for example, a polyether or polyester having one or more functional groups capable of reacting with a carboxyl group and functional groups capable of reacting with an isocyanate group at a linear terminal or branched terminal, for example. Polycarbonate or polybutadiene can be used. Among them, polyester is preferable in order to obtain sufficient coating strength after heat pressing.
Examples of the functional group capable of reacting with the carboxyl group of the compound (g) include a hydroxyl group, an epoxy group, an amino group and an isocyanate group, but a hydroxyl group is preferable in terms of reactivity. Further, examples of the functional group capable of reacting with the isocyanate group of the compound (g) include a hydroxyl group, an amino group, a carboxyl group, an epoxy group, an N-methylol group, an N-alkoxymethyl group and the like, but in terms of reactivity Hydroxyl is preferred. The functional group capable of reacting with the carboxyl group of the compound (g) and the functional group capable of reacting with the isocyanate group may be the same functional group or different functional groups.

Examples of polyesters include terminal hydroxyl group-containing ester compounds obtained by esterification of at least one dicarboxylic acid and at least one polyol such as polyhydric alcohol, polyhydric phenol, or alkoxy modified products thereof, and terminal The ester compound etc. which modified | denatured the hydroxyl group of these into an amino group, a carboxyl group, an epoxy group, N- methylol group, or N- alkoxy methyl group are mentioned.
Examples of dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalic acid, p-hydroxybenzoic acid, p- (hydroxy) benzoic acid, 1,4-cyclohexanedicarboxylic acid, succinic acid, adipic acid And dicarboxylic acids such as azelaiic acid, sebacic acid and dodecanedicarboxylic acid.
Examples of polyhydric alcohols include 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, 1,2-dimethyl- 1,4-butanediol, 2-ethyl-1,4-butanediol, 1,5-pentanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2 2,4-trimethyl-1,3-pentanediol, 3-ethyl-1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,6-hexanediol, 3-methyl-1,6-hexane Diol 1,7-heptanediol, 2-methyl-1,7-heptanediol, 3-methyl-1,7-heptanediol, 4-methyl-1,7-heptanediol, 1,3 -Octanediol, 2-methyl-1, 8-octanediol, 2-ethyl-1, 8-octanediol, 3-methyl-1, 8-octanediol, 4-methyl-1, 8-octanediol, 9-nonanediol, ethylene glycol, propylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, cyclohexane dimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, trimethylolpropane, 1,1,1-trimethylolpropane ethylene Examples thereof include glycol, glycerin, erythritol, xylitol, sorbitol, mannitol and the like.
Examples of polyhydric phenols include catechol, resorcin, hydroquinone, hexyl resorcinol, trihydroxybenzene, dimethylolphenol and the like.
As polyester (polyester polyol) which has two or more hydroxyl groups of a commercial item, Kuraray Co., Ltd. Kuraray Co., Ltd. Kuraray polyol P-510, P-1010, P-1510, P-2010, P-3010, P-4010, for example P-5010, P-6010, P-2011, P-2013, P-520, P-1020, P-2020, P-1012, P-2012, P-530, P-1030, P-2030, PMHC- 2050, PMHC-2050R, PMHC-2070, PMHC-2090, PMSA-1000, PMSA-2000, PMSA-3000, PMSA-4000, F-2010, F-3010, N-2010, PNOA-1010, PNOA-2014, O-2010, Desmofe made by Sumitomo Bayer Urethane Co., Ltd. 650MPA, 651MPA / X, 670, 670BA, 680X, 680MPA, 800, 800MPA, 850, 1100, 1140, 1145, 1150, 1155, 1200, 1300X, 1652, 1700, 1800, RD181, RD181X, C200, Toyobo Co., Ltd. Manufactured by Byron 200, 560, 600, GK 130, GK 860, GK 870, 290, GK 590, GK 780, GK 790, and the like.
In addition, examples of polyethers include polyalkylene glycols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, and terminal hydroxyl groups to amino groups, carboxyl groups, epoxy groups, N-methylol groups or N-alkoxymethyl groups. It includes modified ether compounds. As a polyether (polyether polyol) which has 2 or more of commercially available hydroxyl groups, Desmophen 250U, 550U, 1600U, 1900U, 1915U, 1920D etc. made by Sumitomo Bayer Urethane Co., Ltd. are mentioned, for example.

In addition, examples of polycarbonate include polycarbonate diol represented by the following general formula, and a carbonate compound in which terminal hydroxyl group is modified to amino group, carboxyl group, epoxy group, N-methylol group or N-alkoxymethyl group. .
H- (O-R-OCO-) n R-OH
(R: alkylene chain, diethylene glycol etc.)
As a commercially available polycarbonate having two or more hydroxyl groups, for example, Kuraray Co., Ltd. Kuraray Co., Ltd. Kuraray polyol PNOC-1000, PNOC-2000, PMHC-2050, PMHC-2050R, PMHC-2070, PMHC-2070R, PMHC-2090R, C -2090 and the like.
In addition, as an example of polybutadiene, α, ω-polybutadiene glycol, α, β-polybutadiene glycol, and butadiene in which terminal hydroxyl group is modified to amino group, carboxyl group, epoxy group, N-methylol group or N-alkoxymethyl group Compounds are mentioned.
As commercially available polybutadiene having two or more hydroxyl groups, for example, NISSO-PBG-1000, G-2000, G-3000, GI-1000, GI-2000, GI-3000, GQ-1000, manufactured by Nippon Soda Co., Ltd. GQ-2000 and the like.
Examples of commercially available polybutadiene having two or more epoxy groups include NISSO-PBBF-1000, EPB-13, EPB-1054 and the like manufactured by Nippon Soda Co., Ltd.

The weight average molecular weight in terms of polystyrene of the compound (g) is preferably 500 to 25,000, and more preferably 1,000 to 10,000. When the weight average molecular weight of the compound (g) is 25,000 or less, solubility in a solvent, compatibility with the copolymer (f), reactivity with the copolymer (f) is excellent, and thermal Sufficient coating strength can be obtained after pressing. Moreover, in the case of 500 or more, sufficient flexibility can be given to a sheet | seat and adhesiveness with a base material improves.

The polymer (A1) can be produced by a known method, for example, the compound (g), by reacting the carboxylic acid or carboxylic acid anhydride moiety of the copolymer (f) and the functional group capable of reacting with the carboxyl group of the compound (g). It can be obtained by esterification when the functional group capable of reacting with a carboxyl group is a hydroxyl group or an epoxy group, amidification when it is an amino group, and imidization when it is an isocyanate group. As the solvent, the solvent at the time of synthesis of the copolymer (f) can be used as it is, and further, other solvents may be added or removed depending on the conditions at the time of synthesis, the conditions at the time of coating, etc. It does not matter.
As a reaction catalyst, for example, tertiary amines such as triethylamine, triethanolamine, ethylene diamine and the like are used, and the reaction temperature is preferably 50 to 300 ° C.
The reaction ratio between the copolymer (f) and the compound (g) is such that the functional group capable of reacting with the carboxyl group of the compound (g) with respect to 1 mol of the carboxylic acid or carboxylic anhydride of the copolymer (f) It is preferably 0.01 to 10 moles, more preferably 0.1 to 5 moles, and still more preferably 0.5 to 2 moles.
The copolymer (f) and the compound (g) do not have to be used singly, and plural kinds may be used depending on the purpose and the required physical properties.
Moreover, the weight average molecular weight of polystyrene conversion of a polymer (A1) becomes like this. Preferably it is 5,000-500,000, More preferably, it is 10,000-100,000. When the weight average molecular weight of the polymer (A1) is 500,000 or less, the solubility in a solvent is improved, and when it is 5,000 or more, sufficient coating strength can be obtained after (hot) pressing. .

(Polyisocyanate compound (D))
In the case where the binder resin is a vinyl polymer (A1) having at least one structure selected from polyether, polyester, polycarbonate, or polybutadiene, which has a functional group capable of reacting with an isocyanate group, Furthermore, it is preferable to contain the polyisocyanate compound (D) which has a 2 or more isocyanate group.
The polyisocyanate compound having two or more isocyanate groups is used to crosslink the polymer (A1) and the polymer (A1) and to obtain a sufficient coating strength after heat pressing.
When using it outdoors as a polyisocyanate compound, in order to prevent that a coating film degrades with time, it is preferable to use only an alicyclic or aliphatic compound.
As an alicyclic polyisocyanate compound, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated 4,4'- diphenylmethane diisocyanate etc. are mentioned, for example.
Examples of aliphatic polyisocyanate compounds include trimethylhexamethylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate and the like.
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, polymethylene polyphenyl An isocyanate etc. are mentioned.
As a polyisocyanate compound, you may use the terminal isocyanate adduct of the said compound and glycols or diamines, a biuret modified body, and an isocyanurate modified body.
In particular, when the polyisocyanate compound contains an isocyanurate modified substance, particularly an isocyanurate ring-containing triisocyanate, it is preferable because sufficient coating strength can be obtained after heat pressing. Specifically as the isocyanurate ring-containing triisocyanate, isocyanurate-modified isophorone diisocyanate (for example, Desmodur Z4470 manufactured by Sumitomo Bayer Urethane Co., Ltd.), isocyanurate-modified hexamethylene diisocyanate (for example Sumijure manufactured by Sumitomo Bayer Urethane Co., Ltd.) N3300), isocyanurate-modified toluylene diisocyanate (for example, Sumidul FL-2, FL-3, FL-4, HLBA manufactured by Sumitomo Bayer Urethane Co., Ltd.).

In addition, for example, methanol, ethanol, n-pentanol, ethylene chlorohydrin, isopropyl alcohol, phenol, p-nitrophenol, m-cresol, acetylacetone, ethyl acetoacetate, ε-caprolactam, for example, is used as the isocyanate group of the polyisocyanate compound. Or the like may be used by reacting with a blocking agent such as a block modified product.
Furthermore, as the polyisocyanate compound, at least one kind (h) selected from polyethers, polyesters, polycarbonates or polybutadienes having two or more functional groups capable of reacting with isocyanate groups and diisocyanate compounds having isocyanate groups at both ends (i Both terminal isocyanate prepolymers may be used, which are obtained by reacting them with
In the case where the polyisocyanate compound contains the above-described both-end isocyanate prepolymer, flexibility is obtained with a small amount, and adhesion to the substrate is improved.
As the compound (h), the same compounds as the compound (g) can be used. Compound (i
And the like, for example, toluylene diisocyanate, naphthylene-1,5-diisocyanate, o-toluylene diisocyanate, diphenylmethane diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, m-xylene Diisocyanate, p-xylene diisocyanate, lysine diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, etc. may be mentioned.
The compound (h) and the compound (h) have a ratio such that the isocyanate group of the compound (i) is larger than 1 mol to 1 mol of the functional group capable of reacting with the isocyanate group of the compound (h). i) can be obtained by mixing, heating and stirring for reaction. The polystyrene equivalent weight average molecular weight of the prepolymer is preferably 500 to 50,000, more preferably 1,000 to 50,000, and particularly preferably 1,000 to 10,000.
In the polyisocyanate compound (D), the total number of isocyanate groups is preferably 0.1 times to 5.0 times, more preferably 0, relative to the total number of functional groups of the polymer (A1), depending on the required performance. One kind or a mixture of two or more kinds can be used in such a ratio that the ratio will be 5 times to 3.0 times, particularly preferably 0.8 to 2.0 times.

  Next, the carbon material (B) will be described.

The conductive carbon material (B) in the conductive composition of the present invention is characterized by containing graphite (B-1) and a carbon material (B-2) other than graphite.
The mass ratio of the binder resin (A) to the carbon material (B) is 15: 85 to 35: 65, and preferably 20: 80 to 30: 70.

When the mass ratio of the binder resin is less than 15, the adhesion of the conductive film is lowered, resulting in adhesion failure. On the other hand, when the mass ratio of the binder resin exceeds 35, the contact between carbon materials in the conductive film is inhibited, and the conductivity becomes poor.

When the mass ratio of the binder resin is 20 to 30, adhesion can be exhibited without inhibiting the formation of the conductive network in the conductive film formed of the conductive composition.

As graphite (B-1), artificial graphite, natural graphite, etc. can be used, for example. The artificial graphite is an artificial carbon in which the orientation of the irregularly arranged fine graphite crystals is artificially performed by heat treatment of amorphous carbon, and generally, it is produced mainly using petroleum coke or coal-based pitch coke. Ru. As natural graphite, scale-like graphite, massive graphite, earthy graphite and the like can be used. In addition, expanded graphite obtained by chemically treating scaly graphite (also referred to as expandable graphite) or expanded graphite obtained by heat treatment and expansion, and then obtained by refining or pressing may also be used. It can. Among these graphites, in the case of using for the conductive film of the wiring sheet, flaky graphite such as flaky graphite expanded graphite and exfoliated graphite are preferable from the viewpoint of conductivity.

The surface of these graphites is subjected to surface treatment such as epoxy treatment, urethane treatment, silane coupling treatment, oxidation treatment, etc. in order to increase the affinity to the binder resin as long as the characteristics of the conductive composition of the present invention are not impaired. May be applied.

Moreover, 2-100 micrometers is preferable and, as for the average particle diameter of the graphite to be used, 20-50 micrometers is especially preferable.

If the average particle diameter of the graphite is less than 2 μm, the aspect ratio of the graphite particles is lowered, and the contact between the graphite particles tends to be a point contact, so that the conductive network can not be formed sufficiently. On the other hand, when the average particle diameter of graphite is 100 μm or more, the gaps between the graphite particles become large, the proportion of conductive paths formed between carbon materials other than graphite in the conductive network increases, and conductivity decreases.

  The average particle diameter as referred to in the present invention is a particle diameter (D50) which is 50% when the volume fraction of particles is integrated from the particle having a fine particle diameter in the volume particle size distribution. Particle size distribution meter, for example, a dynamic light scattering type particle size distribution meter ("Microtrack UPA" manufactured by Nikkiso Co., Ltd.) or the like.

  Examples of commercially available graphite include, as flaky graphite, CMX, UP-5, UP-10, UP-20, UP-35N, CSSP, CSPE, CSP, CP, CB-150, CB manufactured by Nippon Graphite Industry Co., Ltd. -100, ACP, ACP-1000, ACB-50, ACB-100, ACB-150, SP-10, SP-20, J-SP, SP-270, HOP, GR-60, LEP, F # 1, F # 2, F # 3, CX-3000 manufactured by Chuetsu Graphite Co., Ltd., FBF, BF, CBR, SSC-3000, SSC-600, SSC-3, SSC, CX-600, CPF-8, CPF-3, CPB- 6S, CPB, 96E, 96L, 96L-3, 90L-3, CPC, S-87, K-3, CF-80, CF-48, CF-32, CP-150, CP-100, CP, HF- 80 HF-48, HF-32, SC-120, SC-80, SC-60, SC-32, EC1500, EC1000, EC500, EC300, EC100, EC50 manufactured by Ito Graphite Industries, 10099M manufactured by Nishimura Graphite, PB -99 and the like. Examples of spherical natural graphite include CGC-20, CGC-50, CGB-20, and CGB-50 manufactured by Nippon Graphite Industry Co., Ltd. Examples of the soil-like graphite include Blue P, AP, AOP, P # 1 manufactured by Nippon Graphite Industry Co., Ltd., APR manufactured by Chuetsu Graphite Co., Ltd., S-3, AP-6, 300F. As artificial graphite, PAG-60, PAG-80, PAG-120, PAG-5, HAG-10W, HAG-150 manufactured by Nippon Graphite Industry Co., Ltd., RA-3000, RA-15, RA- manufactured by Chuetsu Graphite Co., Ltd. 44, GX-600, G-6S, G-3, G-150, G-100, G-48, G-30, G-50, SGP-100, SGP-50, SGP-25 manufactured by SEC Carbon Corporation , SGP-15, SGP-5, SGP-1, SGO-100, SGO-50, SGO-25, SGO-15, SGO-5, SGO-1, SGX-100, SGX-50, SGX-25, SGX -15, SGX-5, SGX-1 are mentioned.

In addition, the content of graphite (B-1) in the conductive composition in the present invention is 75 to 99% by mass in 100% by mass of the carbon material (B), and particularly 100% by mass of the carbon material (B) It is preferable that it is 80-99 mass% in%, and it is further more preferable that it is 90-97.5 mass% in 100 mass% of carbon materials (B).

  When the content of the graphite (B-1) is less than 75% by mass in 100% by mass of the carbon material (B), the decrease in the orientation of the graphite particles by the carbon material (B-2) other than the excessive amount of graphite By occupying most of the conductive network by carbon materials other than graphite, specific high conductivity does not occur. On the other hand, when the content of graphite exceeds 99% by mass in 100% by mass of the carbon material (B), the conductivity in the planar direction by the graphite particles becomes dominant, and the conductivity of the conductive film is leveled off.

  When the content of the graphite (B-1) is 80% by mass or more in 100% by mass of the carbon material (B), it is possible to form a good coating film with few pinholes of the conductive film.

  When the content of the graphite (B-1) is 90 to 97.5 mass% in 100 mass% of the carbon material (B), in addition to the high conductivity in the planar direction by the graphite particles, in addition to an appropriate amount of graphite The carbon material (B-2) of (1) strengthens the vertical conductive network without inhibiting the planar conductivity derived from graphite, and can exhibit very high conductivity.

  When the content of the graphite (B-1) is less than 90% by mass in 100% by mass of the carbon material (B), a coating film with less unevenness of the conductive film can be obtained.

(Carbon materials other than graphite (B-2))
The carbon material other than graphite is not particularly limited, but carbon black is more preferable in terms of particle diameter and specific surface area. Besides, conductive carbon fibers (carbon nanotubes, carbon nanofibers, carbon fibers), fullerenes and the like can be used singly or in combination of two or more.

  As carbon black, furnace black which is produced by continuous thermal decomposition of gaseous or liquid raw materials in a reaction furnace, especially ketjen black made from ethylene heavy oil, raw material gas is burned and the flame is obtained from the bottom of the channel steel Channel black which has been rapidly cooled and deposited, thermal black which is obtained by periodically repeating combustion and thermal decomposition using gas as a raw material, in particular various kinds of acetylene black as a raw material such as acetylene gas alone or It can be used together with more than types. In addition, oxidized carbon black, hollow carbon, and the like that are commonly used can also be used.

  Oxidation treatment of carbon is carried out by treating carbon at high temperature in air or by treating it with nitric acid, nitrogen dioxide, ozone or the like secondarily, such as phenol group, quinone group, carboxyl group, carbonyl group, etc. This treatment directly introduces (covalently bonds) an oxygen-containing polar functional group to a carbon surface, and is generally performed to improve the dispersibility of carbon. However, since the conductivity of carbon generally decreases as the amount of functional groups introduced increases, it is preferable to use carbon which has not been oxidized.

As the specific surface area of the carbon black used is larger, the contact point between carbon black particles is increased, which is advantageous for reducing the internal resistance of the electrode. Specifically, the specific surface area (BET) determined from the adsorption amount of nitrogen is 20 m ² / g or more and 1500 m ² / g or less, preferably 50 m ² / g or more and 1500 m ² / g or less, more preferably 100 m ² It is desirable to use one having a density of at least / g and at most 1500 m ² / g. When carbon black having a specific surface area of less than 20 m ² / g is used, it may be difficult to obtain sufficient conductivity, and carbon black exceeding 1500 m ² / g may be difficult to obtain as a commercial material. is there.

  Further, the particle size of carbon black to be used is preferably 0.005 to 1 μm as a primary particle size, and particularly preferably 0.01 to 0.2 μm. However, the primary particle size referred to here is an average of particle sizes measured with an electron microscope or the like.

Commercially available carbon blacks include, for example, TOKA BLACK # 4300, # 4400, # 4500, # 4500, # 5500 manufactured by Tokai Carbon, Printex L manufactured by Degussa, Raven 7000, 5750, 5250, 5000 ULTRA III, 500 manufactured by Columbian.
0ULTRA, Conductex SCULTRA, Conductex 975 ULTRA, PUERBLACK 100, 115, 205, Mitsubishi Chemical Corporation # 2350, # 2400B, # 2600B, # 3050B, # 3030B, # 3230B, # 3350B, # 3400B, # 5400B, Cabot MONARCH 1400, 1300, 900, Vulcan XC-72R, BlackPearls 2000, Ensaco 250 G, Ensaco 260 G, Ensaco 350 G, SuperP-Li, etc. furnace black made by TIMCAL), Ketjen black made in Lion, EC-300 J, EC-600 JD, etc. Acetylene black such as Denka black, Denka black HS-100, FX-35, etc. Tsu While click and the like, is not limited thereto, may be used in combination of two or more.

  The conductive carbon fiber is preferably one obtained by firing from a petroleum-derived material, but one obtained by firing from a plant-derived material can also be used. Further, as carbon nanotubes, there are single-walled carbon nanotubes which form a tube having a graphene sheet in a single layer and a diameter in the nanometer range, and multi-walled carbon nanotubes in which graphene sheets are multi-layered. Therefore, the diameter of the multi-walled carbon nanotube shows a large value of 30 nm with respect to 0.7-2.0 nm of a typical single-walled carbon nanotube.

As commercially available conductive carbon fibers and carbon nanotubes, vapor-grown carbon fibers such as VGCF manufactured by Showa Denko KK, EC 1.0, EC 1.5, EC 2.0, EC 1.5-P, etc. manufactured by Meijo Nano Carbon Co., Ltd. Single-walled carbon nanotubes, FloTube 9000 made by CNano, FloTube 9100, FloTube 9110, FloTube 9200, NC 7000 made by Nanocyl, 100T made by Knano, and the like.

Next, the solvent will be described. When the binder resin (A) in the conductive composition and the conductive carbon material (B) are uniformly mixed, a solvent can be appropriately used. Such solvents may include organic solvents and water.
Organic solvents 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, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and the like Of ethers, hydrocarbons such as hexane, heptane and octane, aromatics such as benzene, toluene, xylene and cumene, and esters such as ethyl acetate and butyl acetate according to the composition of the conductive composition The thing can be used. Also, two or more solvents may be used.
In the case of adopting a printing coating method in which a conductive composition such as screen printing requires a certain viscosity or more, the viscosity of the organic solvent at 25 ° C. is preferably 30 mPa · s to 75,000 mPa · s. If the content is less than 30 mPa · s, the resin content is small due to high conductivity expression, and good dispersibility of the viscosity and conductive carbon material suitable for coating can not be obtained, and the coating property is insufficient. When the viscosity exceeds 75,000 mPa · s, the dispersibility of the carbon material is significantly reduced because the viscosity is too high. Examples include terpineol, dihydroterpineol, 2,4-diethyl-1,5-pentanediol, 1,3-butylene glycol, isobornyl cyclohexanol. Two or more kinds of high-viscosity solvents shown here may be used, and the viscosity at 25 ° C. such as methyl ethyl ketone, toluene, isopropyl alcohol is 30 mPa · s.
It is also possible to use it in combination with less than low viscosity solvents.

Next, other components will be described. In the conductive composition of the present invention, if necessary, an ultraviolet light absorber, an ultraviolet light stabilizer, a radical scavenger, a filler, a thixotropy-imparting agent, an antiaging agent, an antioxidant, to the extent that the effects of the present invention are not impaired. Agents, antistatic agents, flame retardants, thermal conductivity improvers, plasticizers, anti-sagging agents, antifouling agents, preservatives, bactericides, antifoaming agents, antifoaming agents, leveling agents, antiblocking agents, curing agents, thickeners, Various additives such as pigment dispersants and silane coupling agents may be added.

(Distributor / mixer)
As an apparatus used when obtaining a conductive composition, the disperser and mixer normally used for pigment dispersion etc. can be used.

  For example, mixers such as a disper, homomixer, or planetary mixer; homogenizers such as "CLEARMIX" manufactured by M. Tech. Co., or "FILMIX" manufactured by PRIMIX; paint conditioners (manufactured by Red Devil Co.), ball mills, sand mills Media type disperser such as (Dyno Mill, manufactured by Shinmaru Enterprises Co., Ltd.), Atelier, Pearl Mill (“DCP Mill”, manufactured by Eirich, etc.), Co-ball mill, etc .; Medialess dispersing machines such as "Starburst" manufactured by Machine, "Nanomizer" manufactured by Nanomizer, etc., "Clare SS-5" manufactured by M. Tech., Or "MICROS" manufactured by Nara Machinery; or other roll mills etc. But The present invention is not limited to these.

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

(Conductive film)
The conductive film of the present invention has a conductive film formed of a conductive composition on a substrate.

(Sheet-like substrate)
Although the shape of the sheet-like base material used for electrically conductive film shaping | molding is not specifically limited, An insulating resin film is preferable and what was used for various uses can be selected suitably.

  For example, as materials, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), polyimide, polyvinyl polysalt, polyamide, nylon, OPP (oriented polypropylene), CPP (unoriented polypropylene), etc. may be mentioned, but are particularly limited. There is nothing to do.

  Moreover, as a shape, although the film on a flat plate is generally used, what roughened the surface, what was primer-treated, a hole-like thing, and a mesh-like base material can also be used.

  There is no restriction | limiting in particular as a method of coating a conductive composition on a sheet-like base material, A well-known method can be used.

  Specifically, die coating method, dip coating method, roll coating method, doctor coating method, knife coating method, spray coating method, gravure coating method, screen printing method or electrostatic coating method can be mentioned, and drying is possible. As the method, although it is possible to use standing drying, a blower drier, a hot air drier, an infrared heater, a far infrared heater, etc., it is not particularly limited thereto.

  In addition, rolling may be performed using a lithographic press, a calender roll, or the like after the application, or heating may be performed 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.

(Volume resistivity of conductive film)
The volume resistivity of the conductive film of the present invention is preferably less than 1 × 10 ⁻² Ω · cm. When the volume resistivity is less than 1 × 10 ⁻² Ω · cm, it can be suitably used as an electrode of a battery, a current collector, or a wiring of a battery, an electronic device, or the like.

  EXAMPLES Hereinafter, the present invention will be more specifically described by way of examples. However, the following examples do not limit the scope of the present invention. In addition, "part" in an Example and a comparative example represents a "mass part", Mw means a weight average molecular weight, Tg means a glass transition temperature.

<Synthesis of Binder Resin A-1>
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 condenser, a dropping device, and a nitrogen introducing pipe (manufactured by Kuraray Co., Ltd. "Kuraray Polyol P-2011", Mn = 2011) 455.5 parts, dimethylol butanoic acid 16.5 parts, isophorone diisocyanate 105.2 parts, toluene 140 parts are charged and reacted under a nitrogen atmosphere at 90 ° C for 3 hours. Then, 360 parts of toluene was added to the mixture to obtain a urethane prepolymer solution having an isocyanate group. Next, the obtained urethane prepolymer solution having an isocyanate group in a mixture of 19.9 parts of isophorone diamine, 0.63 parts of di-n-butylamine, 294.5 parts of 2-propanol and 335.5 parts of toluene Add 969.5 parts, react at 50 ° C for 3 hours, then react at 70 ° C for 2 hours, dilute with 126 parts of toluene and 54 parts of 2-propanol, Mw = 61,000, acid value = 10 mg KOH / g, urethane pre A solution of polyurethane resin A-1 was obtained, in which the total equivalent weight of the polyamino compound and the amino group in the reaction terminator with respect to the free isocyanate group at both ends of the polymer is 0.98.

<Synthesis of Binder Resin A-2>
In a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, inlet tube, thermometer, 156.2 g of Pripol 1009 as a polybasic acid compound, 5.5 g of 5-hydroxyisophthalic acid, and priamine as a polyamine compound 146.4 g of 1074 and 100 g of ion exchange water were charged, and the mixture was stirred until the temperature of heat generation became constant. After the temperature was stabilized, the temperature was raised to 110 ° C, and after confirming the outflow of water, the temperature was raised to 120 ° C after 30 minutes, 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 for 3 hours at the same temperature, and held for 1 hour under a vacuum of about 2 kPa to lower the temperature. Finally, an antioxidant is added, and the weight average molecular weight is 24000, the acid value is 13.2 KOHmg / g, the hydroxyl value is 5
. Polyamide resin A-2 having a glass transition temperature of -32 ° C and 5 KOH mg / g was obtained.

In addition, evaluation of resin was performed as follows.
<Method of measuring weight average molecular weight (Mw)>
The measurement of Mw used Tosoh Corp. GPC (gel permeation chromatography) "HPC-8020." GPC is a liquid chromatography that separates and determines a substance dissolved in a solvent (THF; tetrahydrofuran) by the difference in molecular size. In the measurement in the present invention, two “LF-604” (manufactured by Showa Denko KK: GPC column for rapid analysis: 6 mm ID × 150 mm size) are connected in series to the column, and the flow rate is 0.6 ml / min, column temperature The measurement was performed at 40 ° C., and the weight average molecular weight (Mw) was determined in terms of polystyrene.
<Measurement of acid number>
Approximately 1 g of a sample is accurately weighed into a stoppered Erlenmeyer flask, and 100 ml of a mixed solution of toluene / ethanol (volume ratio: toluene / ethanol = 2/1) is dissolved. To this, add phenolphthalein TS as an indicator and hold for 30 seconds. It is then titrated with 0.1 N alcoholic potassium hydroxide solution until the solution is pinkish. The acid value was determined by the following formula (unit: mg KOH / g). Acid value (mg KOH / g) = (5.611 x a x F) / S
However,
S: Amount of sample collected (g)
a: Consumption of 0.1 N alcoholic potassium hydroxide solution (ml)
F: titer of 0.1 N alcoholic potassium hydroxide solution <method of measuring hydroxyl value>
The hydroxyl value is the amount of hydroxyl group contained in 1 g of hydroxyl group-containing resin, expressed by the amount (mg) of potassium hydroxide necessary to neutralize the acetic acid bonded to the hydroxyl group when acetylating the hydroxyl group It is. The hydroxyl value was measured according to JIS K 0070. In the present invention, when the hydroxyl value is calculated, it is calculated in consideration of the acid value as shown in the following formula.
<Measurement of hydroxyl value>
Approximately 1 g of a sample is accurately weighed into a stoppered Erlenmeyer flask, and 100 ml of a mixed solution of toluene / ethanol (volume ratio: toluene / ethanol = 2/1) is dissolved. Furthermore, exactly 5 ml of an acetylating agent (a solution in which 25 g of acetic anhydride was dissolved in pyridine to make a volume of 100 ml) was added and stirred for about 1 hour. To this, add phenolphthalein test solution as an indicator and hold for 30 seconds. It is then titrated with 0.1 N alcoholic potassium hydroxide solution until the solution is pinkish.
The hydroxyl value was determined by the following formula (unit: mg KOH / g).
Hydroxyl value (mg KOH / g) = [{(b−a) × F × 28.05} / S] + D
However,
S: Amount of sample collected (g)
a: Consumption of 0.1 N alcoholic potassium hydroxide solution (ml)
b: Consumption of empty 0.1 N alcoholic potassium hydroxide solution (ml)
F: Potency of 0.1 N alcoholic potassium hydroxide solution D: Acid value (mg KOH / g)
<Method of measuring glass transition temperature>
The binder resin from which the solvent was removed by drying was measured by heating up to −80 to 150 ° C. at 2 ° C./minute using “DSC-1” manufactured by Mettler Toledo Co., Ltd.

<Adjustment of binder resin>
The binder resin used in Examples and Comparative Examples was adjusted to a solution having a solid content of 20% using the solvents shown below. Composition ratio of mixed solvent is described by mass ratio.
Solution of Binder Resin A-1-1: The solution of binder resin A-1 was diluted with toluene / methyl ethyl ketone / 2-propanol (1/1/1) to obtain a solution of binder resin A-1-1.
Solution of Binder Resin A-2-1: Binder resin A-2 was diluted with toluene / 2-propanol (2/1) to obtain a solution of binder resin A-2-1.
Solution of Binder Resin A-3-1: Binder Resin A-3: A solution of Binder Resin A-3-1 by diluting Byron 200 (polyester resin manufactured by Toyobo Co., Ltd.) with toluene / methyl ethyl ketone (1/1) I got

<Conductive composition and conductive film>
Example 1
120 parts of a solution of A-1-1 as binder resin (24 parts of resin solid content), 70 parts of B-1-1: scale-like graphite CB-150 (manufactured by Nippon Graphite Co., Ltd.) as conductive carbon material, other than graphite 6 parts of B-2-1: furnace black # 3050 (manufactured by Mitsubishi Chemical) as a carbon material, and 204 parts of toluene / methyl ethyl ketone / 2-propanol (1/1/1 (mass ratio)) as a solvent The mixture was added and mixed, and then placed in a sand mill for dispersion to obtain a conductive composition (1). And after apply | coating this electroconductive composition (1) on a 100-micrometer-thick PET film used as a sheet-like base material using a doctor blade, it heat-dried and adjusted so that the thickness of a conductive film might be 60 micrometers. . The conductive carbon material contained in the conductive film is 76% by mass.
The obtained conductive film was evaluated by the following method. The evaluation results are shown in Table 1.

(Volume resistivity of conductive film)
The volume resistivity of the conductive film was determined by measuring (JIS-K7194) by a four-terminal method using Loresta GP (manufactured by Mitsubishi Chemical Analytech Co., Ltd.). The evaluation results are shown in Table 1.
◎: “volume resistivity less than 5 × 10 ⁻³ Ω · cm (very good)”
:: “volume resistivity is 5 × 10 ⁻³ Ω · cm or more and less than 1 × 10 ⁻² Ω · cm (good)”
△: “volume resistivity is 1 × 10 ⁻² Ω · cm or more, less than 5 × 10 ⁻² Ω · cm (available)
:: “volume resistivity is 5 × 10 ⁻² Ω · cm or more and less than 1 × 10 ⁻¹ Ω · cm (defect)
×: “volume resistivity is 1 × 10 ⁻¹ Ω · cm or more (very poor)”

(Adhesiveness of conductive film)
Into the conductive film produced above, using a knife, six cross cuts each having a length of 2 mm and a length of 6 were cut at intervals of 2 mm from the surface of the conductive film to the depth to reach the substrate. A pressure-sensitive adhesive tape was attached to the incision and immediately peeled off, and the degree of detachment of the conductive film was determined by visual evaluation. The evaluation results are shown in Table 1, and the evaluation criteria are shown below.
○: "No exfoliation (level without problems in practical use)"
△: "Slightly peeled off (there is a problem but usable level)"
Δ: "Half peeling"
X: "Peeling off in most parts"

<Applicability evaluation>
The conductive composition was evaluated by the coatability evaluation shown below. The conductive film was visually observed, and the unevenness in coating (nonuniformity: evaluated by the density of the coated surface) and the pinhole (evaluated by the presence or absence of a defect in which the conductive film was not applied) was determined according to the following criteria. The evaluation results are shown in Table 1.
(village)
○: Light and shade of the conductive film are not confirmed (good).
Δ: 1 to 3 places of light and shade of conductive film, but very small region (no problem in practical use).
X: four or more places where the density of the conductive film is confirmed, or one or more where the length of the density stripes is 5 mm or more (defect).
(Pin hole)
○: No pinholes are confirmed (good).
Fair: 1 to 3 pinholes, but very small (no problem in practical use).
X: 4 or more pin holes are confirmed, or 1 or more pin holes having a diameter of 1 mm or more (very poor).

(Examples 2 to 40, Comparative Examples 1 to 12)
Conductive compositions (2) to (40) and (a) to (l) were obtained by the same method as the conductive composition (1) at the composition ratios shown in Table 1.
Since Example 16 and Example 27 differ in the kind of binder resin from Example 1, the dilution solvent at the time of electroconductive composition preparation was set to toluene / 2-propanol (2/1).
Since Example 17 and Example 28 differ in the kind of binder resin from Example 1, the dilution solvent at the time of electroconductive composition preparation was made into toluene / methyl ethyl ketone (1/1).

The materials used in the examples are shown below.
<Binder resin (A)>
A-1: Polyurethane resin A-2: Polyamide resin A-3: Polyester resin Byron 200 (manufactured by Toyobo Co., Ltd.)
<Carbon material (B)>
Graphite (B-1)
・ B-1-1: Agate-like graphite CB-150 (manufactured by Nippon Graphite Co., Ltd.) average particle diameter 40 μm (catalog)
・ B-1-2: Agate-like graphite CPB (manufactured by Nippon Graphite Co., Ltd.) average particle diameter 20 μm (catalog)
・ B-1-3: Agate-like graphite FB-100 (manufactured by Nippon Graphite Co., Ltd.) average particle diameter 80 μm (catalog)
・ B-1-4: exfoliated graphite CMX (manufactured by Nippon Graphite Co., Ltd.) average particle diameter 40 μm (catalog)
・ B-1-5: Spheroidal graphite CGB-50 (manufactured by Nippon Graphite Co., Ltd.) average particle diameter 50 μm (catalog)
· B- 1-6: Expanded Graphite LEP (Nippon Graphite Co., Ltd.) Average particle diameter 100μm (Catalog)
・ B-1-7: artificial graphite PAG-5 (manufactured by Nippon Graphite Co., Ltd.) average particle diameter 50 μm (catalog)
<Carbon materials other than graphite (B-2)>
・ B-2-1: furnace black # 3050B (made by Mitsubishi Chemical Corporation)
B-2-2: Denka Black HS-100 (manufactured by Denki Kagaku Kogyo Co., Ltd.)
B-2-3: Ketjen Black EC-300J (manufactured by Lion Specialty Chemicals)
B-2-4: Carbon nanotube VGCF (manufactured by Showa Denko KK)
B-2-5: Ketjen Black EC-600 JD (manufactured by Lion Specialty Chemicals)

As shown in Table 1, in the conductive film of the present invention, adhesion and conductivity were improved more than before, and it was possible to achieve both. From Comparative Examples 1 and 2, it was confirmed that the conductivity was good when the amount of the binder resin mixed was small, but the adhesion to the substrate was reduced. On the other hand, according to Comparative Examples 3 and 4, the adhesion of the conductive film is improved as the mixing amount of the binder resin is increased, but the proportion of the binder resin interposed between the carbon materials is increased in proportion thereto and the contact between the carbon materials It has been confirmed that it inhibits the conductivity and causes a decrease in conductivity.
However, even when the amount of the binder resin mixed is large, it is suppressed within a predetermined range as in Examples 6 and 7, and by appropriately mixing a carbon material other than graphite, it is possible to maintain high adhesion while maintaining high adhesion. It turned out that conductivity can be expressed. It is considered that this is because carbon materials other than graphite were able to be reinforced while maintaining the conductive network of graphite by appropriately interposing between graphite particles. Furthermore, it is considered as another reason that carbon materials other than graphite having a large specific surface area trap extra binder resin present in the conductive film and prevent inhibition of the conductive network.
On the other hand, when Comparative Examples 6 and 8 and Examples 4 and 5 were compared, it was confirmed that the prescribed conductivity could not be exhibited even when the amount of the carbon material other than graphite was too large. This is considered to be caused by an increase in resistance due to the fact that most of the conductive network is occupied by a carbon material other than graphite, in addition to inhibiting the formation of a conductive network between graphite particles by carbon materials other than an excessive amount of graphite.
In addition, when Comparative Examples 5 and 7 and Examples 4 and 5 are compared, it was confirmed that, even when the mixing amount of graphite is too large, predetermined conductivity or adhesion can not be exhibited depending on the mixing ratio with the binder resin. . The reason is considered as follows. In the case where the amount of the binder resin is large, the amount of the carbon material other than graphite mixed is small, and thus it is considered that the formation of the conductive network between the graphite particles by the binder resin is large and the conductivity is leveled off. On the other hand, in the case where the amount of the binder resin is small, it is considered that since the graphite occupies most of the components of the conductive film, the adhesion derived from the binder resin is not expressed.
As described above, in the conductive film composed of the binder resin and the carbon material, excellent conductivity can be obtained between the carbon materials by selectively controlling the mixing ratio of the binder resin in the conductive film, the graphite, and the carbon material other than the graphite. It has been found that it enables the formation of a network and exhibits excellent conductivity and adhesion.

Claims (7)

A conductive composition containing a binder resin (A) and a carbon material (B),
The carbon material (B) contains graphite (B-1) and a carbon material (B-2) other than graphite,
The mass ratio of the solid content of the binder resin (A) to the carbon material (B) is 15: 85 to 35: 65,
The electroconductive composition characterized by the content rate of graphite (B-1) being 75.0-99.0 mass% in 100 mass% of carbon materials (B). The conductive composition according to claim 1, wherein the content of the graphite (B-1) is 80.0 to 99.0 mass% in 100 mass% of the carbon material (B). The conductive composition according to claim 1 or 2, wherein the content of the graphite (B-1) is 90.0 to 97.5 mass% in 100 mass% of the carbon material (B). The mass ratio of solid content of binder resin (A) and a carbon material (B) is 20: 80-30: 70, The conductive composition of any one of Claims 1-3 characterized by the above-mentioned. object. The conductive composition according to any one of claims 1 to 4, wherein the binder resin (A) contains a polyurethane, a polyamide, or a polyester. The conductive composition according to any one of claims 1 to 5, wherein the carbon material (B-2) other than graphite contains carbon black. The electrically conductive film obtained using the electrically conductive composition of any one of Claims 1-6.