Conductive composition, conductive material, conductive film, and conductive article

Abstract

The conductive composition comprises (a) carbon nanotubes, (b) a soluble conductive polymer, and (c) a solvent, and the soluble conductive polymer is (i) or (ii) below. (i) A composite obtained by doping a hydrophobic sulfonic acid compound into a conductive polymer (ii) a conductive polymer having a sulfonic acid group-containing side chain.

Description

Technical Field

[0001] The present invention relates to a conductive composition, a conductive material, a conductive film and a conductive article. Background Art

[0002] Carbon nanotubes are used as conductive additives for electrodes in various batteries, electrodes for touch films, electromagnetic wave shielding materials, antistatic agents, heat dissipation materials, etc. due to their high conductivity and special shape.

[0003] Carbon nanotubes are generally used as conductive materials by drying a dispersion dispersed in water or an organic solvent or a coating film thereof. Carbon nanotubes are widely used as having excellent electrical or thermal conductivity because they conduct electricity or heat through the contact points between the carbon nanotubes.

[0004] In recent years, water-dispersible or organic solvent-dispersible conductive polymers have been developed, and attempts have been made to use these conductive polymers in a composite with carbon nanotubes (Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-170740 Summary of the invention

[0008] In recent years, materials using carbon nanotubes have been required to have better electrical conductivity and thermal conductivity.

[0009] The technology of Patent Document 1 does not necessarily provide a sufficient effect of improving electrical conductivity and thermal conductivity.

[0010] An object of the present invention is to provide a conductive composition that can provide a material having excellent conductivity.

[0011] Another object of the present invention is to provide a conductive composition that can provide a material having excellent thermal conductivity.

[0012] According to the present invention, the following conductive composition and the like are provided.

[0013] 1. A conductive composition comprising (a) carbon nanotubes, (b) a soluble conductive polymer, and (c) a solvent, wherein the soluble conductive polymer is (i) or (ii) below.

[0014] (i) Composites formed by doping conductive polymers with hydrophobic sulfonic acid compounds

[0015] (ii) Conductive polymer having a sulfonic acid group-containing side chain

[0016] 2. The conductive composition according to 1, wherein the hydrophobic sulfonic acid compound in (i) or the sulfonic acid group-containing side chain in (ii) has 6 or more carbon atoms.

[0017] 3. The conductive composition according to 1 or 2, wherein the hydrophobic sulfonic acid compound in (i) has an HLB value of 1 to 8.

[0018] 4. The conductive composition according to any one of 1 to 3, wherein the hydrophobic sulfonic acid compound in (i) is a sulfonic acid compound represented by the following formula (III).

[0019] M(O3SCH(CH2COOR 12 )COOR 13 ) m (III)

[0020] (In formula (III),

[0021] M is a hydrogen atom, an organic free radical or an inorganic free radical,

[0022] m is the valence of M,

[0023] R 12 and R 13 Each independently is a hydrocarbon group or -(R 14 O) r -R 15 The groups shown,

[0024] R 14 is a hydrocarbon group or a silylene group,

[0025] R 15 is a hydrogen atom, a hydrocarbon group or R 16 3Si- represented group,

[0026] R 16 is a hydrocarbon group, 3 R 16 They may be the same or different, and r is an integer greater than 1.)

[0027] 5. The conductive composition according to any one of 1 to 4, wherein the conductive polymer in (i) is polyaniline.

[0028] 6. The conductive composition according to any one of 1 to 5, further comprising (d) a phenolic compound.

[0029] 7. The conductive composition according to any one of 1 to 6, wherein the content of the component (b) is 1 to 400 parts by mass based on 100 parts by mass of the component (a).

[0030] 8. The conductive composition according to any one of 1 to 7, further comprising at least one selected from a resin and an inorganic material.

[0031] 9. A conductive material prepared from the conductive composition according to any one of 1 to 8.

[0032] 10. A film, a molded body, a powder or a granule, comprising the conductive material described in 9.

[0033] 11. A conductive aid for a battery, comprising the conductive material described in 9.

[0034] 12. A conductive film comprising (a) carbon nanotubes and (b) a soluble conductive polymer,

[0035] The soluble conductive polymer is the following (i) or (ii).

[0036] (i) Composites formed by doping conductive polymers with hydrophobic sulfonic acid compounds

[0037] (ii) Conductive polymer having a sulfonic acid group-containing side chain

[0038] 13. A conductive article produced from a mixture of the conductive composition according to any one of 1 to 7 and at least one selected from a resin and an inorganic material.

[0039] 14. A conductive laminate comprising a substrate and a conductive layer comprising the conductive material described in 9, wherein the conductive layer is in contact with the substrate.

[0040] 15. A battery comprising the conductive auxiliary agent for a battery according to 11.

[0041] According to the present invention, a conductive composition capable of obtaining a material having excellent conductivity can be provided.

[0042] Furthermore, according to the present invention, it is possible to provide a conductive composition capable of obtaining a material having excellent thermal conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a diagram schematically showing the mechanism of electrical conductivity development in a coating film obtained from a composition containing carbon nanotubes.

[0044] Figure 2 It is schematically indicated Figure 1 A cross-sectional view of the contact points of carbon nanotubes with each other.

[0045] Figure 3This is a diagram schematically showing a cross section around a contact point between carbon nanotubes of a material obtained from a composition containing a solvent-dispersed conductive polymer.

[0046] Figure 4 This is a diagram schematically showing a mechanism by which conductivity is exhibited in a material obtained from the conductive composition of one embodiment of the present invention. DETAILED DESCRIPTION

[0047] In the present specification, "x to y" represents a numerical range of "x or more and y or less." The upper limit value and the lower limit value described in the numerical range may be arbitrarily combined.

[0048] [Conductive composition]

[0049] A conductive composition according to one embodiment of the present invention includes:

[0050] (a) carbon nanotubes (hereinafter, also referred to as “component (a)”);

[0051] (b) a soluble conductive polymer (hereinafter also referred to as "component (b)"); and

[0052] (c) Solvent (hereinafter, also referred to as “component (c)”).

[0053] Furthermore, the soluble conductive polymer is the following (i) or (ii).

[0054] (i) Composites formed by doping conductive polymers with hydrophobic sulfonic acid compounds

[0055] (ii) Conductive polymer having a sulfonic acid group-containing side chain

[0056] The conductive composition of the present embodiment contains the above-mentioned components (a) to (c), so that the material obtained from the conductive composition shows higher electrical conductivity and thermal conductivity than a material composed of carbon nanotubes alone (a material obtained from a composition containing carbon nanotubes without adding a conductive polymer). The reason for this is presumably as follows.

[0057] like Figure 1 As shown, in a material (such as a coating film, a molded body, etc.) obtained by removing the solvent component from a composition containing carbon nanotubes, the carbon nanotubes 10 are in contact with each other, thereby conducting electricity and heat at their contact points 10a to form a conduction path (conductive region and thermal conduction region), thereby, the material (such as a coating film, a molded body, etc.) obtained after removing the solvent component exhibits conductivity as a whole.

[0058] In the case of a material composed solely of carbon nanotubes, such as Figure 2As shown, electrical and thermal conduction paths are formed only at contact points 10a where carbon nanotubes 10 contact each other.

[0059] on the other hand, Figure 3 This is a diagram schematically showing a material obtained from a composition containing a solvent-dispersed conductive polymer and carbon nanotubes.

[0060] Solvent-dispersed conductive polymers (such as poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS)) are usually dispersed in a solvent in the form of particles of about tens of nanometers. Figure 3 As shown, even if a solvent-dispersed conductive polymer is mixed with carbon nanotubes (usually a single-wall carbon nanotube has a fiber diameter of 0.5 to 3 nm), the solvent-dispersed conductive polymer particles 12 are in point contact with the carbon nanotubes 10 only. Therefore, the conduction paths between the carbon nanotubes 10 are formed only at the contact points 10a between the carbon nanotubes 10 and the contact points between each carbon nanotube 10 and the conductive polymer particles 12.

[0061] Therefore, even if a solvent-dispersed conductive polymer is mixed with carbon nanotubes, the increase in the conduction path between the carbon nanotubes 10 is small, so the electrical conductivity and thermal conductivity are not improved much even if the conductive polymer is added.

[0062] On the other hand, a material obtained by removing the solvent component from a conductive composition using the soluble conductive polymer of the present embodiment is as follows: Figure 4 As shown, the soluble conductive polymer 11 is attached to the periphery including the contact points between the carbon nanotubes 10, and is in a state of covering a part of the surface of the carbon nanotubes 10, or in a state of covering the entire surface of the carbon nanotubes 10. Therefore, in the material (e.g., a coating film, a molded body, etc.) obtained by removing the solvent component of the conductive composition of the present embodiment, the carbon nanotubes 10 are electrically connected to each other not only through the contact points and the periphery thereof, but also through the soluble conductive polymer 11 existing between the carbon nanotubes 10.

[0063] That is, in the material obtained by removing the solvent component of the conductive composition of this embodiment, Figure 4 As shown in FIG. 1 , the conduction paths between the carbon nanotubes 10 are formed in a planar shape by the soluble conductive polymer 11 interposed between the carbon nanotubes 10. Figure 2 , Figure 3 Compared with the state shown, the conduction path formed per unit volume is increased.

[0064] Therefore, in the material obtained by removing the solvent component from the conductive composition of the present embodiment, Figure 2 , Figure 3Compared with the state shown, the contact resistance when current is applied is lowered, and the resistance value of the material as a whole after the solvent component is removed is suppressed to a low level, so excellent electrical conductivity is exhibited, and excellent thermal conductivity is also exhibited.

[0065] It should be noted that “soluble conductive polymer” refers to a conductive polymer that is soluble in a solvent component (organic solvent or water). The conductive polymer being dissolved in the solvent component means that the conductive polymer is dispersed in the solvent at a molecular level.

[0066] Therefore, if Figure 4 As shown, it is believed that in the material obtained by removing the solvent component from the conductive composition containing the soluble conductive polymer, the soluble conductive polymer 11 is attached to the periphery of the carbon nanotubes 10, thereby becoming a state of coating the surface of each carbon nanotube 10, and at the contact points between the carbon nanotubes 10, the conductive path is formed into a planar shape.

[0067] In addition, when a conductive polymer having a hydrophilic dopant component (such as polystyrene sulfonic acid (PSS)) is used as a conductive polymer mixed with carbon nanotubes, or when a conductive polymer whose molecule as a whole is hydrophilic is used, since the affinity with the surface of the hydrophobic carbon nanotubes is low, it is difficult for the surface of each carbon nanotube to be covered with the conductive polymer as a whole.

[0068] In contrast, the conductive composition of the present embodiment uses (i) a composite formed by doping a hydrophobic sulfonic acid compound in a conductive polymer or (ii) a conductive polymer having a side chain containing a sulfonic acid group as a soluble conductive polymer, thereby having a high affinity for the surface of the hydrophobic carbon nanotube.

[0069] It is speculated that through this affinity, Figure 4 As shown, the soluble conductive polymer 11 easily adheres to the periphery of each carbon nanotube 10 , and after the solvent is removed, the surface of each carbon nanotube 10 is covered, so that a conductive path is formed between each carbon nanotube 10 in a planar shape.

[0070] The conductive composition of the present embodiment is considered to have high conductivity and thermal conductivity that cannot be obtained with conventional combinations of carbon nanotubes and conductive polymers due to the synergistic effect of carbon nanotubes having high conductivity and thermal conductivity and conductive polymers having both solubility and hydrophobicity.

[0071] Therefore, the conductive polymer used can be used in the conductive composition of the present embodiment without particular limitation as long as it has both solubility and hydrophobicity, and the effects obtained by the conductive composition of the present embodiment can be obtained.

[0072] Hereinafter, each component of the conductive composition of this embodiment will be described.

[0073] (Component (a): carbon nanotubes)

[0074] Examples of the carbon nanotube include single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs), multi-walled carbon nanotubes (MWCNTs), and carbon nanofibers.

[0075] As the carbon nanotube, one of these may be used alone, or two or more of them may be used in combination.

[0076] The fiber diameter of the carbon nanotube is not particularly limited. From the viewpoint of obtaining good conductivity in the material obtained from the conductive composition, for example, the fiber diameter of a single-walled carbon nanotube (SWCNT) may be 0.1 to 50 nm, 0.3 to 10 nm, or 0.5 to 3 nm.

[0077] The fiber diameter of the multi-walled carbon nanotube (MWCNT) may be 1 to 500 nm, 3 to 300 nm, or 5 to 100 nm.

[0078] The fiber diameter of the double-walled carbon nanotube (DWCNT) may be 0.2 to 100 nm, 0.5 to 80 nm, or 1 to 50 nm.

[0079] The fiber diameter of the carbon nanofiber (CNF) may be 100 to 1000 nm, 120 to 800 nm, or 150 to 500 nm.

[0080] In this specification, the fiber diameter of carbon nanotubes refers to the outer diameter of the fiber.

[0081] The fiber diameter of carbon nanotubes and the fiber length described below can be determined by observing the carbon nanotubes using a scanning transmission electron microscope, selecting any 100 carbon nanotubes in the observed image, measuring their outer diameters and lengths, and calculating the arithmetic mean of the outer diameters and the arithmetic mean of the lengths.

[0082] The fiber length of the carbon nanotubes is not particularly limited, and from the viewpoint of obtaining good conductivity in a material obtained from the conductive composition, the fiber length may be, for example, 0.1 μm or more, 5 μm or more, or 10 μm or more.

[0083] The content of component (a) may be 5 mass % or more, 10 mass % or more, or 15 mass % or more, and may be 95 mass % or less, 93 mass % or less, 90 mass % or less, 80 mass % or less, or 70 mass % or less, relative to 100 mass % of the total of component (a) and component (b).

[0084] When the content of the component (a) is within the above range relative to 100 mass % of the total of the component (a) and the component (b), a material obtained from the conductive composition can obtain good conductivity.

[0085] The content of the component (a) relative to 100 mass % of the entire composition may be, for example, 0.1 mass % or more, 0.15 mass % or more, or 0.18 mass % or more.

[0086] The carbon nanotubes can be used in the conductive composition of the present embodiment in a state dispersed in a dispersion medium. In this case, the dispersion medium of the carbon nanotubes is brought into the conductive composition of the present embodiment and is contained in the solvent of the component (c) in the conductive composition.

[0087] The dispersion medium of the carbon nanotubes is not particularly limited as long as it can uniformly disperse the carbon nanotubes. For example, preferred are glycol ethers such as dipropylene glycol dimethyl ether, methyl ethyl cellosolve, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (PGMEA), ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and isophorone, alcohols such as methanol, ethanol, isopropanol, and ethylene glycol, N-methylpyrrolidone, N,N-dimethylformamide, water, and the like.

[0088] (Component (b): soluble conductive polymer)

[0089] As the soluble conductive polymer, the following (i) first aspect or (ii) second aspect can be mentioned.

[0090] (i) Composites formed by doping conductive polymers with hydrophobic sulfonic acid compounds

[0091] (ii) Conductive polymer having a sulfonic acid group-containing side chain

[0092] (i) First method

[0093] The soluble conductive polymer of the first embodiment is a composite material in which a hydrophobic sulfonic acid compound is doped in a conductive polymer.

[0094] The soluble conductive polymer of the first embodiment is hydrophobic and has excellent solubility in a solvent (organic solvent or water). Therefore, after removing the solvent contained in the conductive composition, the surface of each carbon nanotube can be covered with the soluble conductive polymer.

[0095] As the conductive polymer of the first embodiment, polyaniline, polythiophene, polypyrrole and their derivatives can be cited. These may have a substituent or may not have a substituent. These may be used alone or in combination of two or more.

[0096] As the conductive polymer, polyaniline is preferred from the viewpoint of versatility and economic efficiency.

[0097] From the viewpoint of obtaining good conductivity in the composite, the weight average molecular weight of the polyaniline is preferably 10,000 or more, more preferably 20,000 or more.

[0098] More preferably, it is 30,000 or more and 1,000,000 or less,

[0099] More preferably, it is 40,000 or more and 1,000,000 or less, and particularly preferably 52,000 or more and 1,000,000 or less.

[0100] The weight average molecular weight of polyaniline is measured by the method described in Examples.

[0101] The polyaniline may or may not have a substituent, but is preferably an unsubstituted polyaniline from the viewpoint of versatility and economic efficiency.

[0102] When the substituent has a substituent, for example, there can be mentioned a straight-chain or branched hydrocarbon group such as methyl, ethyl, hexyl, octyl, etc.; an alkoxy group such as methoxy, ethoxy, etc.; an aryloxy group such as phenoxy, etc.; and a halogenated hydrocarbon such as trifluoromethyl (-CF3 group).

[0103] The hydrophobic sulfonic acid compound can be used without any particular limitation in terms of chemical structure as long as it can form a complex that exhibits solubility in a solvent by being doped with a conductive polymer.

[0104] In the present specification, the term "hydrophobicity" means an HLB (Hydrophilic-Lipophilic Balance) value within the range of 1 to 8.

[0105] When the sulfonic acid compound has 6 or more carbon atoms, the HLB value is within the range of 1 to 8, indicating hydrophobicity.

[0106] In the following description, a hydrophobic sulfonic acid compound is referred to as a hydrophobic sulfonic acid compound.

[0107] The hydrophobic sulfonic acid compound is doped into substituted or unsubstituted polyaniline as a proton donor to form a polyaniline composite.

[0108] The fact that the hydrophobic sulfonic acid compound is doped into polyaniline as a proton donor can be confirmed by ultraviolet-visible-near-infrared spectroscopy and X-ray photoelectron spectroscopy.

[0109] The sulfonic acid compound as a proton donor may be used without any particular limitation in terms of chemical structure as long as it has acidity sufficient to generate carriers in polyaniline.

[0110] The number of carbon atoms in the hydrophobic sulfonic acid compound may be 6 or more, 7 or more, 8 or more, or 10 or more, or 35 or less, 30 or less, 25 or less, or 20 or less.

[0111] When the number of carbon atoms in the hydrophobic sulfonic acid compound is within the above range, the composite obtained by doping the hydrophobic sulfonic acid compound with the conductive polymer exhibits hydrophobicity as a whole and exhibits excellent solubility in a solvent (organic solvent or water).

[0112] The HLB value of the hydrophobic sulfonic acid compound may be 1.0 to 8.0, 2.0 to 7.0, 3.0 to 5.0, or 3.5 to 4.8.

[0113] When the HLB value of the hydrophobic sulfonic acid compound is within the above range, the composite obtained by doping the hydrophobic sulfonic acid compound with the conductive polymer exhibits hydrophobicity as a whole and exhibits excellent solubility in a solvent (organic solvent or water).

[0114] The HLB value of the sulfonic acid compound is calculated by the formula based on the following Griffin method.

[0115] HLB value = 20 × total formula weight of hydrophilic part / molecular weight

[0116] Examples of the hydrophobic sulfonic acid compound (proton donor) include a sulfonic acid compound (proton donor) represented by the following formula (I).

[0117] M(XAR n ) m (I)

[0118] (In formula (I), M is a hydrogen atom, an organic free radical or an inorganic free radical.

[0119] X is -SO3 - A is a hydrocarbon group which may contain a substituent.

[0120] R is each independently -R 1 、-OR 1 、-COR 1 、-COOR 1 、-CO(COR 1 ), or -CO (COOR 1 ) is a substituent shown in FIG.

[0121] R 1 is a hydrocarbon group having 4 or more carbon atoms which may contain a substituent, a silyl group, an alkylsilyl group, -(R 2 O) x -R 3 The group shown, or -(OSiR 3 2)x -OR 3 (R 2 is an alkylene group, R 3 wherein each of them is a hydrocarbon group which may be the same or different, and x is an integer greater than 1).

[0122] n is an integer greater than or equal to 2.

[0123] m is the valence of M. )

[0124] In the above formula (I), M is a hydrogen atom, an organic free radical or an inorganic free radical.

[0125] Examples of the organic radical include a pyridinium group, an imidazolium group, an anilinium group, etc. Examples of the inorganic radical include sodium, lithium, potassium, cesium, ammonium, etc.

[0126] A is a hydrocarbon group which may have a substituent.

[0127] Examples of the hydrocarbon group include a linear or branched alkyl group (e.g., ethylene) having 1 to 24 carbon atoms (preferably 1 to 8, more preferably 1 to 4); an alkenyl group; a cycloalkyl group which may have a substituent, such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a menthyl group, etc.; a bicycloalkyl group or a polycycloalkyl group which may be condensed, such as a bicyclohexyl group, a norbornyl group, an adamantyl group, etc.; an aromatic ring-containing aryl group which may have a substituent, such as a phenyl group, a p-toluenesulfonyl group, a thienyl group, a pyrrolinyl group, a pyridyl group, a furyl group, etc.; a diaryl group or a polyaryl group which may be condensed, such as a naphthyl group, anthracenyl group, a fluorenyl group, a 1,2,3,4-tetrahydronaphthyl group, an indanyl group, a quinolyl group, an indolyl group, etc.; and corresponding (n+1)-valent groups such as an alkylaryl group.

[0128] R is each independently -R 1 、-OR 1 、-COR 1 、-COOR 1 、-CO(COR 1 ), or -CO (COOR 1 ) is a substituent shown in FIG.

[0129] R 1 is a hydrocarbon group having 4 or more carbon atoms (e.g., 4 to 8 or 4 to 12 carbon atoms) which may have a substituent (e.g., an alkyl group having 1 to 4 carbon atoms (preferably a methyl group, an ethyl group, or a propyl group)), a silyl group, an alkylsilyl group, -(R 2 O) x -R 3 The group shown, or -(OSiR 3 2) x -OR 3 (R 2 is an alkylene group, R 3wherein each of them is a hydrocarbon group which may be the same or different, and x is an integer greater than 1).

[0130] As R 1 Examples of the hydrocarbon group include linear or branched butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, pentadecyl, eicosyl and the like.

[0131] n is an integer of 2 or more (eg, 2 to 4 or 2 to 3).

[0132] m is the valence of M.

[0133] The sulfonic acid compound represented by the above formula (I) is hydrophobic, and a composite obtained by doping the sulfonic acid compound with a conductive polymer exhibits excellent solubility in a solvent (organic solvent or water).

[0134] Therefore, by using the sulfonic acid compound represented by formula (I) as the hydrophobic sulfonic acid compound, the surface of each carbon nanotube can be covered with the soluble conductive polymer (a composite of the conductive polymer doped with the sulfonic acid compound represented by formula (I)).

[0135] The hydrophobic sulfonic acid compound (proton donor) represented by formula (I) is preferably a dialkylbenzenesulfonic acid, a dialkylnaphthalenesulfonic acid, a sulfophthalate, or a sulfonic acid compound (proton donor) represented by the following formula (II) (organic protonic acid or a salt thereof).

[0136] M(XCR 4 (CR 5 2COOR 6 )COOR 7 ) p (II)

[0137] In the above formula (II), M and X are the same as those in formula (I).

[0138] p is the valence of M.

[0139] R 4 and R 5 are each independently a hydrogen atom, a hydrocarbon group or R 8 3Si- represented group (here, R 8 is a hydrocarbon group, 3 R 8 can be the same or different).

[0140] As R 4 and R 5 The hydrocarbon group includes a linear or branched alkyl group having 1 to 24 carbon atoms; an aryl group including an aromatic ring; an alkylaryl group, and the like.

[0141] R 8 The hydrocarbon group and R 4and R 5 The hydrocarbon groups are the same.

[0142] R 6 and R 7 Each independently is a hydrocarbon group or -(R 9 O) q -R 10 The group shown [here, R 9 is a hydrocarbon group or a silylene group, R 10 is a hydrogen atom, a hydrocarbon group or R 11 3Si- represented group (R 11 is a hydrocarbon group, 3 R 11 may be the same or different), q is an integer greater than 1].

[0143] As R 6 and R 7 The hydrocarbon group includes a linear or branched alkyl group having 1 to 24 carbon atoms, preferably 4 or more carbon atoms (eg 4 to 10 or 4 to 14); an aryl group including an aromatic ring; an alkylaryl group, and the like.

[0144] As R 6 and R 7 Specific examples of the hydrocarbon group include linear or branched butyl, pentyl, hexyl, octyl (eg, 2-ethylhexyl), decyl, and the like.

[0145] As R 9 The hydrocarbon group is a linear or branched alkylene group having 1 to 24 carbon atoms; an arylene group containing an aromatic ring; an alkylarylene group; an arylalkylene group, and the like.

[0146] In addition, as R 10 and R 11 The hydrocarbon group, with R 4 and R 5 The same is true for the case of q. Preferably, q is an integer of 1 to 10.

[0147] As R 6 and R 7 =R 9 O) q -R 10 Specific examples of the proton donor acid represented by formula (II) in the case of a group represented by include acids represented by the following formulas.

[0148]

Chemical formula 1

[0149]

[0150] (In the formula, X is a group represented by -SO3, etc.)

[0151] The sulfonic acid compound represented by the above formula (II) is hydrophobic, and a composite obtained by doping the sulfonic acid compound with a conductive polymer exhibits excellent solubility in a solvent (organic solvent or water).

[0152] Therefore, by using the sulfonic acid compound represented by formula (II) as the hydrophobic sulfonic acid compound, the surface of each carbon nanotube can be covered with the soluble conductive polymer (a composite of the conductive polymer doped with the sulfonic acid compound represented by formula (II)).

[0153] The hydrophobic sulfonic acid compound (proton donor) (organic protonic acid or a salt thereof) represented by the above formula (II) is preferably a sulfosuccinic acid derivative represented by the following formula (III).

[0154] M(O3SCH(CH2COOR 12 )COOR 13 ) m (III)

[0155] In the above formula (III), M and m are the same as in the above formula (I).

[0156] R 12 and R 13 Each independently is a hydrocarbon group or -(R 14 O) r -R 15 The group shown [here, R 14 is a hydrocarbon group or a silylene group, R 15 is a hydrogen atom, a hydrocarbon group or R 16 3Si- represented group (here, R 16 is a hydrocarbon group, 3 R 16 may be the same or different), r is an integer greater than 1].

[0157] R 12 and R 13 The hydrocarbon group and R 6 and R 7 The hydrocarbon groups are the same.

[0158] R 14 The hydrocarbon group and R 9 In addition, R 15 and R 16 The hydrocarbon group and R 4 and R 5 The hydrocarbon groups are the same.

[0159] r is preferably an integer of 1-10.

[0160] R 12 and R 13 =R 14 O)r -R 15 Specific examples of sulfosuccinic acid derivatives represented by formula (III) when the group represented by R 6 and R 7 =R 9 O) n -R 10 The proton donor represented by the formula (II) is the same as the group represented by the formula (II).

[0161] R 12 and R 13 The hydrocarbon group and R 6 and R 7 The hydrocarbon groups are the same as those of , preferably butyl, hexyl, 2-ethylhexyl, decyl, etc.

[0162] The sulfonic acid compound represented by the above formula (III) is hydrophobic, and a composite obtained by doping the sulfonic acid compound with a conductive polymer exhibits excellent solubility in a solvent (organic solvent or water).

[0163] Therefore, by using the sulfonic acid compound represented by formula (III) as the hydrophobic sulfonic acid compound, the surface of each carbon nanotube can be covered with the soluble conductive polymer (a composite of the conductive polymer doped with the sulfonic acid compound represented by formula (III)).

[0164] In addition, as the hydrophobic sulfonic acid compound (proton donor), as a substance other than the sulfonic acid compound (proton donor) represented by the above formula (I) to (III), for example, camphorsulfonic acid (HLB value: 7.0), dinonylnaphthalenesulfonic acid (HLB value: 3.5), and adamantanesulfonic acid (HLB value: 7.5) can be used.

[0165] When the hydrophobic sulfonic acid compound is used as a proton donor to polyaniline, the doping rate of the hydrophobic sulfonic acid compound (proton donor) to polyaniline is preferably 0.30 or more and 0.65 or less, more preferably 0.32 or more and 0.60 or less, further preferably 0.33 or more and 0.57 or less, and particularly preferably 0.34 or more and 0.55 or less. If the doping rate is 0.30 or more, the solubility of the polyaniline composite in the organic solvent is sufficiently high.

[0166] The doping rate is defined by (the number of moles of the hydrophobic sulfonic acid compound (proton donor) doped in the polyaniline) / (the number of moles of the monomer unit of the polyaniline). For example, a doping rate of 0.5 for a polyaniline composite containing unsubstituted polyaniline and a hydrophobic sulfonic acid compound (proton donor) means that one hydrophobic sulfonic acid compound (proton donor) is doped for every two monomer unit molecules of the polyaniline.

[0167] If the molar numbers of the hydrophobic sulfonic acid compound (proton donor) and the polyaniline monomer units in the polyaniline composite can be measured, the doping rate can be calculated.

[0168] In this embodiment, since the proton donor is an organic sulfonic acid, the molar number of sulfur atoms derived from the proton donor and the molar number of nitrogen atoms derived from the monomer unit of polyaniline are quantified by organic element analysis and the doping rate can be calculated by taking the ratio of these values.

[0169] The polyaniline composite preferably contains unsubstituted polyaniline and sulfonic acid as a proton donor, and satisfies the following formula (5).

[0170] 0.32≤S5 / N5≤0.60 (5)

[0171] (In the formula, S5 is the total number of moles of sulfur atoms contained in the polyaniline composite, and N5 is the total number of moles of nitrogen atoms contained in the polyaniline composite. The above-mentioned numbers of moles of nitrogen atoms and sulfur atoms are values ​​measured by organic element analysis.)

[0172] The soluble conductive polymer of the first embodiment may be used alone or in combination of two or more.

[0173] The method for producing the soluble conductive polymer of the first embodiment is not particularly limited, and the soluble conductive polymer can be produced, for example, by the method for producing the soluble conductive polymer of the first embodiment described below.

[0174] For example, the hydrophobic sulfonic acid compound (proton donor), aniline corresponding to the polyaniline, and a surfactant (e.g., a nonionic emulsifier) ​​as required are dissolved in a water-immiscible organic solvent (e.g., a hydrocarbon solvent (preferably toluene or xylene)), an acidic aqueous solution (e.g., an aqueous phosphoric acid solution) is added thereto, the reaction liquid having two liquid phases of the water-immiscible organic solvent and water is stirred, and a polymerization initiator (e.g., ammonium persulfate) is added to carry out polymerization.

[0175] After the polymerization, the water-immiscible organic solvent is phase-separated by standing the reaction mixture to obtain a water-immiscible organic solvent solution of the polyaniline composite.

[0176] The solution is transferred to an evaporator, and the volatile components are evaporated to obtain a polyaniline composite (protonated polyaniline).

[0177] (ii) Second method

[0178] The soluble conductive polymer of the second embodiment is a conductive polymer having a side chain containing a sulfonic acid group (sulfonic acid group-containing side chain).

[0179] In addition, in the following description, the conductive polymer having a side chain containing a sulfonic acid group is also referred to as a sulfonic acid group-containing conductive polymer.

[0180] The soluble conductive polymer of the second embodiment has high hydrophobicity and excellent solubility in a solvent (organic solvent or water). Therefore, after removing the solvent contained in the conductive composition, the surface of each carbon nanotube can be covered with the soluble conductive polymer.

[0181] Examples of the main chain monomer of the sulfonic acid group-containing conductive polymer include 3,4-ethylenedioxythiophene (EDOT), aniline, and anisidine.

[0182] Examples of the sulfonic acid group-containing side chain covalently bonded to the main chain include an alkylsulfonic acid group and an alkyl ethersulfonic acid group.

[0183] The carbon number of the side chain containing a sulfonic acid group may be, for example, 1 to 15 or 2 to 10.

[0184] The content of the component (b) may be 1 part by mass or more, 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, or 20 parts by mass or more, and may be 2000 parts by mass or less, 1000 parts by mass or less, 800 parts by mass or less, 500 parts by mass or less, or 400 parts by mass or less, based on 100 parts by mass of the component (a).

[0185] The content of the component (b) may be 1 to 1000 parts by mass, 1 to 400 parts by mass, or 15 to 400 parts by mass based on 100 parts by mass of the component (a).

[0186] When the content of the component (b) is within the above range relative to 100 parts by mass of the component (a), a material obtained from the conductive composition can obtain good conductivity.

[0187] The content of the component (b) may be 0.01 to 20 mass %, 0.05 to 15 mass %, 0.08 to 10 mass %, or 0.15 to 10 mass % relative to 100 mass % of the entire composition.

[0188] (Component (c): solvent)

[0189] The conductive composition according to one embodiment of the present invention contains a solvent.

[0190] The solvent is not particularly limited as long as it can dissolve component (b), and may be water or an organic solvent. From the viewpoint of dissolving component (b), an organic solvent is preferred. The organic solvent may be a water-soluble organic solvent or an organic solvent substantially immiscible with water (a water-immiscible organic solvent).

[0191] The solvent may contain a solvent introduced into the conductive composition as a dispersion medium for the carbon nanotubes as the component (a).

[0192] The solvent for dissolving the component (b) and the dispersion medium for the component (a) may be the same as or different from each other.

[0193] The water-soluble organic solvent may be a protic polar solvent or an aprotic polar solvent, and examples thereof include alcohols such as isopropanol, 1-propanol, 1-butanol, 2-butanol, 2-pentanol, benzyl alcohol, alkoxy alcohols (e.g., 1-methoxy-2-propanol, 3-methoxy-1-butanol, 3-methoxy-3-methylbutanol, 1-ethoxy-2-propanol, 2-ethoxy-1-propanol, 1-butoxy-2-propanol), and ethylene glycol; ketones such as acetone; ethers such as tetrahydrofuran, dioxane, ethylene glycol mono-tert-butyl ether, dipropylene glycol dimethyl ether, and propylene glycol monomethyl ether acetate (PGMEA); and N-methylpyrrolidone.

[0194] In one embodiment, among the water-soluble organic solvents, glycol ethers such as dipropylene glycol dimethyl ether and propylene glycol monomethyl ether acetate (PGMEA) are preferred.

[0195] Examples of water-immiscible organic solvents include hydrocarbon solvents such as hexane, benzene, toluene, xylene, ethylbenzene, tetralin, and IPSOLVENT 1620; halogen-containing solvents such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, and tetrachloroethane; ester solvents such as ethyl acetate, isobutyl acetate, n-butyl acetate, butyl butyrate, and ethyl lactate; ketone solvents such as methyl isobutyl ketone (MIBK), diisobutyl ketone (DIBK), methyl ethyl ketone, cyclopentanone, and cyclohexanone; ether solvents such as cyclopentyl methyl ether, 4-methyltetrahydropyran, and 1,2-diethoxyethane. In addition, as the hydrocarbon solvent, an isoparaffin solvent containing one or more isoparaffins can be used.

[0196] Among them, toluene, xylene, methyl isobutyl ketone, chloroform, trichloroethane, ethyl acetate, tetrahydrofuran, cyclohexanone, and methyl ethyl ketone are preferred because they have excellent solubility of the component (b).

[0197] The polyaniline composite in component (b) can be dissolved even in alcohols such as isopropyl alcohol, 1-butanol, 2-butanol, 2-pentanol, benzyl alcohol, and alkoxy alcohols. Alcohols are preferred over aromatics such as toluene in terms of reducing environmental burden.

[0198] When an organic solvent is used as the solvent, a mixed organic solvent of a water-immiscible organic solvent and a water-soluble organic solvent at a mass ratio of 99 to 1:1 to 99 can be used. The use of a mixed organic solvent is preferred because it can prevent the generation of gel during storage and enable long-term storage.

[0199] As the water-immiscible organic solvent of the mixed organic solvent, a low-polarity organic solvent can be used, and the low-polarity organic solvent is preferably a hydrocarbon solvent such as hexane and toluene; a halogen-containing solvent such as chloroform; or an isomeric paraffin solvent.

[0200] As the water-soluble organic solvent of the mixed organic solvent, a highly polar organic solvent can be used, for example, preferably alcohols such as methanol, ethanol, isopropanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 3-methoxy-1-butanol, 1-ethoxy-2-propanol, 2-ethoxy-1-propanol, 1-butoxy-2-propanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone; ethers such as tetrahydrofuran, diethyl ether, cyclopentyl methyl ether, 4-methyltetrahydropyran, ethylene glycol mono-tert-butyl ether.

[0201] The mixed organic solvent may contain one or two or more water-immiscible organic solvents, or may contain one or two or more water-soluble organic solvents.

[0202] The component (c) may be used alone or in combination of two or more.

[0203] The content of the component (c) may be 50 to 99.8 mass %, 55 to 95 mass %, or 70 to 90 mass % relative to 100 mass % of the entire composition.

[0204] (Ingredient (d): phenolic compound)

[0205] In one embodiment, the conductive composition further comprises a phenolic compound in addition to the above components (a) to (c). By comprising the phenolic compound, the conductivity of a material obtained using the conductive composition can be further improved.

[0206] The phenolic compound is not particularly limited, and is a compound represented by ArOH (where Ar is an aryl group or a substituted aryl group). Specifically, examples thereof include substituted phenols such as phenol, o-cresol, m-cresol or p-cresol, o-ethylphenol, m-ethylphenol or p-ethylphenol, o-propylphenol, m-propylphenol or p-propylphenol, o-butylphenol, m-butylphenol or p-butylphenol, o-chlorophenol, m-chlorophenol or p-chlorophenol, o-tert-amylphenol, m-tert-amylphenol or p-tert-amylphenol, salicylic acid, hydroxybenzoic acid, and hydroxynaphthalene; polyphenolic compounds such as catechol and resorcinol; and polymer compounds such as phenolic resins, polyphenols, and poly(hydroxystyrene).

[0207] In addition, a phenolic compound represented by the following formula (3) can be used.

[0208]

Chemical formula 2

[0209]

[0210] (In formula (3), n1 is an integer of 1 to 5 (preferably 1 to 3).

[0211] R 21 They are alkyl having 1 to 10 carbon atoms (preferably 2 to 8 carbon atoms, more preferably 3 to 7 carbon atoms), alkenyl having 2 to 20 carbon atoms, alkylthio having 1 to 20 carbon atoms, cycloalkyl having 3 to 10 carbon atoms, aryl having 6 to 20 carbon atoms, alkylaryl having 7 to 20 carbon atoms, or arylalkyl having 7 to 20 carbon atoms.

[0212] Next, for the above R 21 Provide explanation.

[0213] Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, and a tert-amyl group.

[0214] Examples of the alkenyl group include substituents having an unsaturated bond in the molecule of the above-mentioned alkyl group.

[0215] Examples of the cycloalkyl group include cyclopentane and cyclohexane.

[0216] Examples of the alkylthio group include a methylthio group and an ethylthio group.

[0217] Examples of the aryl group include a phenyl group and a naphthyl group.

[0218] Examples of the alkylaryl group and the arylalkyl group include substituents obtained by combining the above-mentioned alkyl groups and aryl groups.

[0219] Among these groups, R 21 , preferably methyl or ethyl.

[0220] In addition, a phenolic compound represented by the following formula (3') can be used.

[0221]

Chemical formula 3

[0222]

[0223] (In formula (3'), R 22 It is an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms.

[0224] R in formula (3') 22The specific example is the same as R in the above formula (3) 21 same.

[0225] The component (d) may be used alone or in combination of two or more.

[0226] The content of component (d) may be 1 to 50 mass %, 5 to 45 mass %, 10 to 40 mass %, 10 to 30 mass %, or 10 to 20 mass % based on 100 mass % of the entire conductive composition.

[0227] (Component (e): acidic substance and / or salt of acidic substance)

[0228] In one embodiment, the conductive composition may further contain an acid species different from the hydrophobic sulfonic acid compound (proton donor) in addition to the above-mentioned components (a) to (c), and may further contain one or more selected from acidic substances and salts of acidic substances (hereinafter also referred to as "component (e)"). This component is generally used as a heat stabilizer, and can further improve the heat resistance of a conductive material such as a conductive film obtained using the conductive composition.

[0229] The component (e) may be added to the conductive composition, or may be contained in a coating film or the like formed from the conductive composition by immersing the coating film or the like in a solution in which an acidic substance and / or a salt of an acidic substance is dissolved.

[0230] The acidic substance may be any of an organic acid which is an acid of an organic compound and an inorganic acid which is an acid of an inorganic compound, and is preferably an organic acid. The acidic substance is preferably an organic acid containing one or more sulfonic acid groups.

[0231] The organic acid having a sulfonic acid group is preferably a cyclic, chain or branched alkylsulfonic acid, a substituted or unsubstituted aromatic sulfonic acid or a polysulfonic acid having one or more sulfonic acid groups.

[0232] Examples of the alkylsulfonic acid include methanesulfonic acid and ethanesulfonic acid. The alkyl group is preferably a linear or branched alkyl group having 1 to 18 carbon atoms.

[0233] Examples of the aromatic sulfonic acid include aromatic sulfonic acids having 6 to 20 carbon atoms, such as sulfonic acids having a benzene ring, sulfonic acids having a naphthalene skeleton, and sulfonic acids having an anthracene skeleton. Examples of the aromatic sulfonic acid include substituted or unsubstituted benzenesulfonic acid, substituted or unsubstituted naphthalenesulfonic acid, and substituted or unsubstituted anthracenesulfonic acid.

[0234] The substituent may be a substituent selected from an alkyl group (eg, an alkyl group having 1 to 20 carbon atoms), an alkoxy group (eg, an alkoxy group having 1 to 20 carbon atoms), a hydroxyl group, a nitro group, a carboxyl group, and an acyl group, and may be substituted with one or more substituents.

[0235] Specifically, examples of the aromatic sulfonic acid include compounds represented by the following formula (4) or (5).

[0236]

Chemical formula 4

[0237]

[0238] (In formula (4), l is 1 or more, m is an integer of 0 or more and 5 or less, and n is an integer of 0 or more and 5 or less. When one of m or n is 0, the other is 1 or more.)

[0239]

Chemical formula 5

[0240]

[0241] (In formula (5), q is 1 or more, p is an integer of 0 or more and 7 or less, and R is each independently an alkyl group having 1 to 20 carbon atoms, a carboxyl group, a hydroxyl group, a nitro group, a cyano group, or an amino group.)

[0242] In the formula (4), l is preferably 1 to 3. In the formula (4), m is preferably 1 to 3. In the formula (4), n is preferably 0 to 3.

[0243] In the formula (5), q is preferably 1 to 3. In the formula (5), p is preferably 0 to 3. In the formula (5), R is preferably an alkyl group having 1 to 20 carbon atoms, a carboxyl group, or a hydroxyl group.

[0244] Examples of the aromatic sulfonic acid include 4-sulfophthalic acid, 5-sulfoisophthalic acid, 5-sulfosalicylic acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 2-hydroxy-6-naphthalenesulfonic acid, p-phenolsulfonic acid, toluenesulfonic acid, p-xylene-2-sulfonic acid, 4,4'-biphenyldisulfonic acid, dibenzofuran-2-sulfonic acid, flavianic acid, (+)-10-camphorsulfonic acid, monoisopropylnaphthalenesulfonic acid, 1-pyrenesulfonic acid, etc. Among them, 4-sulfophthalic acid, 5-sulfosalicylic acid, 5-sulfoisophthalic acid, 2-naphthalenesulfonic acid, dibenzofuran-2-sulfonic acid, flavianic acid, 2-hydroxy-6-naphthalenesulfonic acid, and 1-pyrenesulfonic acid are preferred from the viewpoint of improving heat resistance.

[0245] Examples of the salt of the acidic substance include the salts of the compounds listed above, and examples of the counter ion of the salt include sodium, lithium, potassium, cesium, ammonium, calcium, and barium.

[0246] Component (e) may be a hydrate.

[0247] The component (e) may be used alone or in combination of two or more.

[0248] When the component (e) is contained, the content of the component (e) is preferably 0.01 to 10% by mass, more preferably 0.02 to 5% by mass, and even more preferably 0.05 to 3% by mass, based on 100% by mass of the entire composition.

[0249] When component (e) is included, from the viewpoint of heat resistance, the mass ratio of the content of component (b) to the content of component (e) ("content of component (b)":"content of component (e)") can be 1:0.01 to 1:1, preferably 1:0.05 to 1:0.5, and more preferably 1:0.07 to 1:0.1.

[0250] In one embodiment, the conductive composition may contain various additives such as a binder in addition to the above components (a) to (e). As the binder, a known binder can be used.

[0251] In one embodiment, the conductive composition may further include at least one selected from a resin and an inorganic material in addition to the above components (a) to (e).

[0252] As the resin and the inorganic material, known resins and inorganic materials used to obtain a molded body including carbon nanotubes can be used without particular limitation.

[0253] In one embodiment, the conductive composition contains various additives such as a binder in addition to the above components (a) to (e), and may contain at least one selected from a resin and an inorganic material.

[0254] The composition of one embodiment of the present invention may be composed essentially of components (a), (b) and (c) and optionally one or more components selected from (d) and (e). In this case, other inevitable impurities may be contained within a range that does not impair the effects of the present invention.

[0255] For example, 70% by mass or more, 80% by mass or more, 90% by mass or more, 98% by mass or more, 99% by mass or more, 99.5% by mass or more, 99.9% by mass or more, or 100% by mass of the composition of one embodiment of the present invention can be composed of

[0256] Ingredients (a) to (c),

[0257] Ingredients (a) to (d),

[0258] Components (a) to (c), (e) or

[0259] Composed of components (a) to (e).

[0260] The method for preparing the composition of one embodiment of the present invention is not particularly limited, and the composition can be obtained by mixing the above-mentioned components (a) to (e) by a known method.

[0261] The mixing method is not particularly limited, and the mixing can be performed, for example, by stirring and mixing a mixed solution containing the above-mentioned components (a) to (e) by a known method. The stirring temperature and stirring speed are not particularly limited.

[0262] In addition, the order of mixing is not particularly limited. For example, components (c) to (e) may be mixed to obtain a mixed solvent, component (b) may be added thereto to obtain a solution, component (a) may be added to the solution, and the mixture may be stirred and mixed. Alternatively, component (a) may be added to the mixed solvent to obtain a solution, component (b) may be added to the solution, and the mixture may be stirred and mixed.

[0263] [Conductive film]

[0264] A conductive film according to one embodiment of the present invention includes:

[0265] (a) carbon nanotubes; and

[0266] (b) Soluble conductive polymers,

[0267] The soluble conductive polymer is the following (i) or (ii).

[0268] (i) Composites formed by doping conductive polymers with hydrophobic sulfonic acid compounds

[0269] (ii) Conductive polymer having a sulfonic acid group-containing side chain

[0270] A conductive film according to one embodiment of the present invention is formed using the conductive composition described above.

[0271] For example, a conductive film can be formed by applying the conductive composition of one embodiment of the present invention on a substrate and drying to remove component (c) (solvent). A conductive laminate can also be prepared by applying the conductive composition on a substrate such as glass, a resin film, a sheet, or a nonwoven fabric having a desired shape.

[0272] The thickness of the conductive film is usually 1 mm or less, preferably 10 nm to 50 μm.

[0273] From the viewpoint of exerting the effect as a conductive material, the surface resistance of the conductive film of one embodiment of the present invention is, for example, 500Ω / □ or less, 450Ω / □ or less, 400Ω / □ or less, 300Ω / □ or less, 200Ω / □ or less, or 150Ω / □ or less.

[0274] The surface resistance of the conductive film was measured by the method described in Examples.

[0275] As a method for applying the composition, a known method such as casting, spraying, dipping, doctor blade, bar coating, spin coating, electrostatic spinning, screen printing, gravure printing, etc. can be used.

[0276] In addition, a step of immersing the conductive film (coating film) in a solution containing the component (e) and drying the solution may be provided. In this case, the component (e) is preferably a compound represented by the formula (4) or a salt thereof.

[0277] The solution used in the impregnation may contain a solvent.

[0278] The solvent is not particularly limited as long as it can dissolve component (e), and examples thereof include water, alcohol solvents, ketone solvents, ether solvents, ester solvents, etc. The solvent may be used alone or in combination of two or more.

[0279] Specific examples of the solvent include methanol, ethanol, isopropanol, n-butanol, 1-methoxy-2-propanol, 3-methoxy-1-butanol, 3-methoxy-3-methylbutanol, 1-ethoxy-2-propanol, ethyl acetate, butyl acetate, MIBK, methyl ethyl ketone (MEK), ethylene glycol mono-tert-butyl ether, propylene glycol monomethyl ether acetate, and dipropylene glycol monomethyl ether.

[0280] The content of the component (e) in the solution for immersion is preferably 10 to 1200 parts by mass, more preferably 30 to 700 parts by mass, and even more preferably 70 to 400 parts by mass, based on 1 part by mass of the composition obtained by removing the solvent.

[0281] If the amount exceeds 1,200 parts by mass, the acidic substance in the coating film becomes excessive, which may cause degradation of the polyaniline main chain and reduce the conductivity.

[0282] The content of component (e) in the solution for immersion is preferably 0.1% by mass to 10% by mass, more preferably 0.3% by mass to 6% by mass, and even more preferably 0.7% by mass to 3.5% by mass.

[0283] Examples of the impregnation method include dipping.

[0284] The immersion time is preferably 1 minute or longer, more preferably 3 minutes or longer and 200 minutes or shorter, and still more preferably 7 minutes or longer and 30 minutes or shorter. The immersion temperature is preferably 5°C to 50°C.

[0285] Drying after impregnation is preferably performed in an oven, a hot plate, or the like.

[0286] The drying temperature is preferably 80 to 200°C, more preferably 100 to 170°C.

[0287] The drying time is preferably 1 to 180 minutes, more preferably 3 to 60 minutes. Heating may be performed under reduced pressure as required. The drying temperature and drying time are not particularly limited and may be appropriately selected according to the material used.

[0288] As described above, the component (e) may be added to the conductive composition or contained in a conductive film obtained from the conductive composition. The component (e) may be added to the conductive composition and further contained in a conductive film obtained from the conductive composition.

[0289] That is, the conductive film of one embodiment of the present invention sometimes contains a component (e) added to the composition before film formation (hereinafter, sometimes referred to as component (e1)) and a component (e) added by immersion after film formation (hereinafter, sometimes referred to as component (e2)). Components (e1) and (e2) may be the same or different. In different cases, for example, component (e1) is a compound represented by the above formula (5), and component (e2) is a compound represented by the above formula (4).

[0290] The conductive film according to one embodiment of the present invention can be used as a battery material.

[0291] [Conductive laminate]

[0292] The conductive laminate according to one embodiment of the present invention includes a substrate and a conductive layer including the conductive material according to one embodiment of the present invention, wherein the conductive layer is in contact with the substrate.

[0293] For example, by applying the conductive composition of one embodiment of the present invention to a substrate such as glass, a resin film, a sheet, or a nonwoven fabric having a desired shape and removing the solvent, a conductive laminate having a conductive layer (conductive film) can be manufactured. The conductive laminate can be processed into a desired shape by a known method such as vacuum forming or pressure forming, thereby manufacturing a conductive article. From the viewpoint of forming, the substrate is preferably a resin film, a sheet, or a nonwoven fabric.

[0294] As a coating method of the conductive composition to the substrate, known methods such as casting, spraying, dipping, scraper, rod coating, spin coating, electrostatic spinning, screen printing, gravure printing, etc. can be used. When the above-mentioned coating film is dried, the coating film can be heated according to the type of solvent. For example, it is heated at a temperature of less than 250°C, preferably more than 50 and less than 200°C under air flow, and then heated under reduced pressure and nitrogen flow as needed. The heating temperature and heating time are not particularly limited and can be appropriately selected according to the material used.

[0295] In addition, the composition of one embodiment of the present invention can also be used to form a self-supporting molded body without a substrate.

[0296] [Conductive materials]

[0297] The conductive material according to one embodiment of the present invention is produced from the conductive composition according to one embodiment of the present invention.

[0298] The conductive material of one embodiment of the present invention is obtained by removing the component (c) (solvent) from the conductive composition of one embodiment of the present invention, for example.

[0299] As a method for removing the component (c) (solvent), for example, the conductive composition is applied on a substrate and then dried.

[0300] A film, a molded body, a powder or granules according to one embodiment of the present invention includes the conductive material according to one embodiment of the present invention.

[0301] That is, the shape of the conductive material of one embodiment of the present invention is not particularly limited and can be selected according to the purpose, and examples thereof include films, molded bodies, powders, and granules.

[0302] The conductive material of one embodiment of the present invention can be used as, for example, a conductive additive for a battery. Examples of the shape of the conductive additive for a battery include a film, a powder, or a granule.

[0303] [Conductive articles]

[0304] The conductive article according to one embodiment of the present invention is made of a mixture of the conductive composition according to one embodiment of the present invention and at least one selected from a resin and an inorganic material.

[0305] The conductive article of one embodiment of the present invention is obtained by mixing the conductive composition of one embodiment of the present invention with at least one selected from a resin and an inorganic material, and, for example, drying the mixture to remove the component (c) (solvent).

[0306] The shape of the conductive article is not particularly limited and can be appropriately determined according to the intended use.

[0307] [Battery]

[0308] A battery according to one embodiment of the present invention includes a conductive aid for a battery, and the conductive aid for a battery includes the conductive material according to one embodiment of the present invention.

[0309] The battery is not particularly limited, and an example thereof includes a lithium secondary battery.

[0310] Example

[0311] Production Example 1 (Production of Polyaniline Composite)

[0312] 32.4 g of "NEOCOL SWC" (sodium di-2-ethylhexyl sulfosuccinate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., HBL value: 3.66), 13.3 g of aniline, and 0.9 g of "Sorbon T-20" (a nonionic emulsifier having a polyoxyethylene sorbitan fatty acid ester structure, manufactured by Toho Chemical Industry Co., Ltd.) were added to a 1000 mL separable flask and dissolved in 320.4 g of toluene. 450 g of an 8.5 mass % phosphoric acid aqueous solution was added thereto, and the reaction liquid having two liquid phases of toluene and water was stirred, and the internal temperature of the reaction liquid was cooled to 5°C. When the internal temperature of the reaction liquid reached 5°C, a solution prepared by dissolving 39.3 g of APS (ammonium persulfate) in 90.2 g of an 8.5 mass % phosphoric acid aqueous solution was added using a dropping funnel while stirring the reaction liquid, and the solution was stirred for 4 hours while the internal temperature of the solution was kept at 5°C. After stopping stirring, the contents were transferred to a separatory funnel, and the aqueous phase and the toluene phase (organic phase) were allowed to stand and separate.

[0313] After separation, the toluene phase (organic layer) was washed once with 180.3 g of an 8.5 mass % phosphoric acid aqueous solution and five times with 328.0 g of ion-exchanged water, thereby obtaining a polyaniline composite toluene solution.

[0314] The solution was transferred to an evaporator, heated in a hot water bath at 60° C., and reduced in pressure to evaporate volatile components to obtain a polyaniline composite (protonated polyaniline). The weight average molecular weight (Mw) of the polyaniline in the polyaniline composite 1 was 73,000.

[0315] The weight average molecular weight of polyaniline is measured as follows.

[0316] 1.65-1.85 g of lithium bromide was dissolved in 2000 mL of NMP (N-methyl-2-pyrrolidone) to prepare a 0.01 M lithium bromide NMP solution. 14 μL of triethylamine was added to 10 mL of the 0.01 M lithium bromide NMP solution, and the mixture was stirred and dissolved to prepare a uniform solution. In addition, 50 μL of the polyaniline complex toluene solution obtained in Preparation Example 1 was added dropwise, stirred and mixed, and then passed through a 0.45 μm filter to prepare a sample for gel permeation chromatography (GPC) measurement.

[0317] The GPC measurement was performed using a GPC column (“Shodex KF-806M” manufactured by Showa Denko K.K., two connected) under the following measurement conditions.

[0318] Solvent: NMP containing 0.01M LiBr

[0319] Flow rate: 0.70mL / min

[0320] Column temperature: 60°C

[0321] Injection volume: 100 μL

[0322] UV detection wavelength: 270nm

[0323] The weight average molecular weight obtained by the above method is a polystyrene (PS) conversion value.

[0324] The doping ratio of the proton donor (sodium di-2-ethylhexylsulfosuccinate) to polyaniline was 0.36.

[0325] The HBL value of “NEOCOL SWC” (sodium di-2-ethylhexyl sulfosuccinate, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was calculated based on the following formula (A).

[0326] HBL value = 20 × (formula weight of SO3Na part) / molecular weight... (A)

[0327] The HLB value of sodium di-2-ethylhexylsulfosuccinate (molecular weight: 443.61, formula weight of SO3Na part: 81.07) based on formula (A) is formula (A)=20×81.07 / 443.61=3.66.

[0328] Example 1 (Preparation of Conductive Composition)

[0329] 70 g of cyclohexanone (component (c)) (manufactured by Tokyo Chemical Industry) and 30 g of 4-tert-amylphenol (component (d)) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were mixed until uniform to prepare a mixed solution A. 1.6 g of the polyaniline composite (component (b)) obtained in Production Example 1 was dissolved in 98.4 g of the mixed solution A to obtain a polyaniline solution A (polyaniline composite concentration: 1.6 mass %).

[0330] 2 g of a single-walled carbon nanotube (SWCNT) dispersion (component (a)), 0.05 g of polyaniline solution A, and 1.95 g of mixed solution A were stirred and mixed to obtain a conductive composition (a solution containing a CNT / polyaniline composite).

[0331] In addition, the mixing ratio of each component contained in the single-walled carbon nanotube (SWCNT) dispersion liquid is shown below.

[0332] Carbon nanotubes (SWCNT): 0.4 mass%

[0333] Alkyl acetalized polyvinyl alcohol: 1.0 mass%

[0334] Propylene glycol monomethyl ether acetate (PGMEA): 98.6% by mass

[0335] (Evaluation of conductive film (surface resistance))

[0336] The conductive composition (solution containing a CNT / polyaniline composite) obtained in Example 1 was applied to an easily adhesive PET substrate using a bar coater under the following conditions and then dried to obtain a conductive film (film of a CNT / polyaniline composite).

[0337] Rod coating conditions

[0338] Coating device: Mini coater "MC30" (manufactured by Hohsen Co., Ltd.)

[0339] Coating speed: 30mm / s

[0340] Applicator spacing: 150μm

[0341] Drying conditions: 150℃, 10min

[0342] The surface resistance of the conductive film (CNT / polyaniline composite film) obtained above was measured using a resistivity meter "Loresta GP" (manufactured by Mitsubishi Chemical Corporation) using a four-probe method.

[0343] Table 1 shows the measurement results.

[0344] The film thickness of the conductive film was measured using a linear gauge sensor (manufactured by Ono Sakuki Co., Ltd.). The film thickness of the conductive film is shown in Table 1.

[0345] Examples 2 to 5, Comparative Example 1

[0346] A conductive composition (a solution containing a CNT / polyaniline composite) was obtained in the same manner as in Example 1 except that the mixing ratios of the single-walled carbon nanotube (SWCNT) dispersion, polyaniline solution A, and mixed solution A used in Example 1 were changed to the ratios shown in Table 1, respectively.

[0347] Conductive films (films of CNT / polyaniline composites) were prepared and evaluated in the same manner as in Example 1, except that the conductive compositions (solutions containing CNT / polyaniline composites) of Examples 2 to 5 and Comparative Example 1 were used instead of the conductive composition of Example 1. The results of the measurement of the film thickness and surface resistance of each conductive film are shown in Table 1.

[0348]

Table 1

[0349]

[0350] In Table 1, "CHN" means cyclohexanone, and "tAP" means 4-tert-amylphenol. In Table 1 and Table 2 described below, "E+XX" means "×10 XX ”.

[0351] Example 6 (Preparation of composition)

[0352] 70 g of tetrahydrofuran (component (c)) (manufactured by Tokyo Chemical Industry) and 30 g of 4-tert-amylphenol (component (d)) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were mixed until uniform to prepare a mixed solution B. 0.4 g of the polyaniline composite (component (b)) obtained in Production Example 1 was dissolved in 99.6 g of the mixed solution B to obtain a polyaniline solution B (polyaniline composite concentration: 0.4 mass %).

[0353] 2 g of the same single-walled carbon nanotube (SWCNT) dispersion (component (a)) (single-walled carbon nanotube concentration: 0.4 mass %) as used in Example 1 and 2 g of polyaniline solution B were stirred and mixed to obtain a conductive composition (solution containing a CNT / polyaniline composite).

[0354] (Evaluation of conductive film (surface resistance))

[0355] The conductive composition (solution containing a CNT / polyaniline composite) obtained in Example 6 was applied to a glass substrate by spin coating under the following conditions and then dried to obtain a conductive film (film of a CNT / polyaniline composite).

[0356] Spin coating conditions

[0357] Coating equipment: Spin coater "MS-A100" (manufactured by MIKASA Co., Ltd.)

[0358] Speed: 500rpm

[0359] Drying conditions: 150℃, 5min

[0360] The surface resistance of the conductive film (CNT / polyaniline composite film) obtained above was measured using a resistivity meter “Loresta GP” (manufactured by Mitsubishi Chemical Corporation) using a four-probe method.

[0361] The film thickness of the conductive film was measured using a linear gauge sensor (manufactured by Ono Sakuki Co., Ltd.). Table 2 shows the film thickness of the conductive film.

[0362] Example 7

[0363] 0.4 g of the polyaniline composite obtained in Production Example 1 was dissolved in 99.6 g of tetrahydrofuran to obtain a polyaniline solution C (polyaniline composite concentration: 0.4 mass %).

[0364] A conductive composition (a solution containing a CNT / polyaniline composite) was obtained in the same manner as in Example 6 except that the polyaniline solution B in Example 6 was replaced with the polyaniline solution C in the subsequent steps.

[0365] A conductive film (CNT / polyaniline composite film) was prepared and evaluated in the same manner as in Example 6, except that the conductive composition (CNT / polyaniline composite solution) of Example 7 was used instead of the conductive composition of Example 6. The film thickness and surface resistance of the conductive film are shown in Table 2.

[0366] Comparative Example 2

[0367] 2 g of the same single-walled carbon nanotube (SWCNT) dispersion (carbon nanotube concentration: 0.4 mass %) as used in Example 1 and 2 g of tetrahydrofuran (component (c)) (manufactured by Tokyo Chemical Industry) were mixed to obtain a conductive composition (CNT dispersion).

[0368] A conductive film (CNT-only film) was prepared and evaluated in the same manner as in Example 6 except that the conductive composition (CNT dispersion) of Comparative Example 2 was used instead of the conductive composition of Example 6. Table 2 shows the measurement results of the film thickness and surface resistance of the conductive film.

[0369]

Table 2

[0370]

[0371] In addition, in Table 2, "THF" represents tetrahydrofuran, and "tAP" represents 4-tert-amylphenol.

[0372] As shown in Tables 1 and 2, the conductive films obtained from the conductive compositions of Examples 1 to 7 in which the polyaniline composite is blended with carbon nanotubes have a surface resistance suppressed to a low value, and excellent conductivity can be obtained, compared with Comparative Examples 1 and 2 in which only carbon nanotubes are used. In addition, as the blending amount of the polyaniline composite increases, the surface resistance of the conductive film obtained decreases, and the conductive film of Example 5 in which the blending amount of the polyaniline composite is the highest has a surface resistance significantly lower than that of the conductive film of Example 1.

[0373] Industrial Applicability

[0374] The conductive composition of the present invention and the conductive film of the present invention can be used for a conductive auxiliary agent, a touch film electrode, an electromagnetic wave shielding material, an antistatic agent, a battery, a capacitor, and the like.

[0375] Several embodiments and / or examples of the present invention have been described in detail above, but those skilled in the art can easily make various changes to these illustrative embodiments and / or examples without departing from the new teachings and effects of the present invention. Therefore, these various changes are included in the scope of the present invention.

[0376] The contents of the documents described in this specification and the applications serving as the basis for the Paris Convention priority claim of the present application are all incorporated into this specification by reference.

Claims

1. A conductive composition comprising: (a) Carbon nanotubes; (b) soluble conductive polymer; and (c) solvent, The soluble conductive polymer is (i) or (ii) below, (i) A composite material in which a hydrophobic sulfonic acid compound is doped into a conductive polymer; (ii) A conductive polymer having a side chain containing a sulfonic acid group.

2. The conductive composition according to claim 1, wherein The hydrophobic sulfonic acid compound in (i) or the sulfonic acid group-containing side chain in (ii) has 6 or more carbon atoms.

3. The conductive composition according to claim 1 or 2, wherein The HLB value of the hydrophobic sulfonic acid compound in the above (i) is 1-8.

4. The conductive composition according to any one of claims 1 to 3, wherein The hydrophobic sulfonic acid compound in the above (i) is a sulfonic acid compound represented by the following formula (III): M(O3SCH(CH2COOR) 12 )COOR 13 ) m (III) In formula (III), M is a hydrogen atom, an organic free radical or an inorganic free radical, m is the valence of M, R 12 and R 13 Each independently is a hydrocarbon group or -(R 14 O) r -R 15 The groups shown, R 14 is a hydrocarbon group or a silylene group, R 15 is a hydrogen atom, a hydrocarbon group or R 16 3Si- represented group, R 16 is a hydrocarbon group, 3 R 16 They may be the same or different, and r is an integer of 1 or greater.

5. The conductive composition according to any one of claims 1 to 4, wherein The conductive polymer in the above (i) is polyaniline. 6 . The conductive composition according to claim 1 , further comprising (d) a phenolic compound.

7. The conductive composition according to any one of claims 1 to 6, wherein The content of the component (b) is 1 to 400 parts by mass based on 100 parts by mass of the component (a). 8 . The conductive composition according to claim 1 , further comprising at least one material selected from the group consisting of resins and inorganic materials. 9 . A conductive material, comprising the conductive composition according to claim 1 . 10 . A film, a molded body, a powder or a granule, comprising the conductive material according to claim 9 . 11 . A conductive aid for a battery, comprising the conductive material according to claim 9 .

12. A conductive film comprising: (a) carbon nanotubes; and (b) Soluble conductive polymers, The soluble conductive polymer is (i) or (ii) below, (i) A composite material in which a hydrophobic sulfonic acid compound is doped into a conductive polymer; (ii) A conductive polymer having a side chain containing a sulfonic acid group. 13 . A conductive article, comprising a mixture of the conductive composition according to claim 1 and at least one material selected from a resin and an inorganic material.

14. A conductive laminate comprising: substrate; and A conductive layer comprising the conductive material according to claim 9, The conductive layer is in contact with the substrate. 15 . A battery comprising the conductive auxiliary agent for a battery according to claim 11 .

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