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

Abstract

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

Description

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

[0001] The present invention relates to an electrically conductive composition, an electrically conductive material, an electrically conductive film, and an electrically conductive article.

[0002] Due to their high electrical conductivity and unique shape, 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. Carbon nanotubes are generally used as conductive materials by drying dispersions of carbon nanotubes in water or organic solvents or coating films thereof, and are widely used as materials with excellent electrical or thermal conductivity due to electrical conduction or thermal conduction through contact points between carbon nanotubes.

[0003] In recent years, conductive polymers dispersed in water or organic solvents have been developed, and attempts have been made to use these conductive polymers in combination with carbon nanotubes (Patent Document 1).

[0004] JP 2015-170740 A

[0005] In recent years, there has been a demand for materials using carbon nanotubes with better electrical and thermal conductivity. Even with the technology of Patent Document 1, the effect of improving electrical and thermal conductivity was not necessarily sufficient.

[0006] An object of the present invention is to provide an electrically conductive composition from which a material having excellent electrical conductivity can be obtained. Another object of the present invention is to provide an electrically conductive composition from which a material having excellent thermal conductivity can be obtained.

[0007] According to the present invention, the following conductive compositions and the like are provided. 1. A conductive composition comprising (a) carbon nanotubes, (b) a soluble conductive polymer, and (c) a solvent, wherein the soluble conductive polymer is either (i) or (ii) below: (i) a composite in which a conductive polymer is doped with a hydrophobic sulfonic acid compound; or (ii) a conductive polymer having a sulfonic acid group-containing side chain. 2. The conductive composition according to 1, wherein the hydrophobic sulfonic acid compound in (i) above or the sulfonic acid group-containing side chain in (ii) above has 6 or more carbon atoms. 3. The conductive composition according to 1 or 2, wherein the hydrophobic sulfonic acid compound in (i) above has an HLB value of 1 to 8. 4. The conductive composition according to any one of 1 to 3, wherein the hydrophobic sulfonic acid compound in (i) above is a sulfonic acid compound represented by the following formula (III): M(O ３ SCH (CH ２ COOR １２ ) COOR １３ ) ｍ (III) (In formula (III), M is a hydrogen atom, an organic radical, or an inorganic radical, m is the valence of M, and R １２ and R １３ are each independently a hydrocarbon group or -(R １４ O) ｒ -R １５ R is a group represented by １４ is a hydrocarbon group or a silylene group, R １５ is a hydrogen atom, a hydrocarbon group, or R １６ ３ is a group represented by Si—, and R １６ is a hydrocarbon group, and three R １６may be the same or different, and r is an integer of 1 or more.) 5. The conductive composition according to any one of 1 to 4, wherein the conductive polymer in (i) is polyaniline. 6. The conductive composition according to any one of 1 to 5, further comprising (d) a phenolic compound. 7. The conductive composition according to any one of 1 to 6, wherein the content of component (b) is 1 to 400 parts by mass per 100 parts by mass of component (a). 8. The conductive composition according to any one of 1 to 7, further comprising at least one selected from the group consisting of resins and inorganic materials. 9. A conductive material produced from the conductive composition according to any one of 1 to 8. 10. A film, a molded body, a powder, or a granule comprising the conductive material according to 9. 11. A conductive additive for a battery comprising the conductive material according to 9. 12. A conductive film comprising (a) carbon nanotubes and (b) a soluble conductive polymer, wherein the soluble conductive polymer is (i) or (ii) below. (i) A composite in which a conductive polymer is doped with a hydrophobic sulfonic acid compound. (ii) A conductive polymer having a sulfonic acid group-containing side chain. 13. A conductive article made from a mixture of the conductive composition according to any one of items 1 to 7 and at least one selected from the group consisting of a resin and an inorganic material. 14. A conductive laminate comprising a substrate and a conductive layer made of the conductive material according to item 9, wherein the conductive layer and the substrate are in contact with each other. 15. A battery comprising the conductive auxiliary for batteries according to item 11.

[0008] According to the present invention, there is provided a conductive composition from which a material having excellent electrical conductivity can be obtained. Also, according to the present invention, there is provided a conductive composition from which a material having excellent thermal conductivity can be obtained.

[0009] Fig. 2 is a diagram schematically showing the mechanism of electrical conductivity development in a coating film obtained from a composition containing carbon nanotubes. Fig. 3 is a diagram schematically showing a cross section of a contact point between carbon nanotubes in Fig. 1. Fig. 4 is a diagram schematically showing a cross section around a contact point between carbon nanotubes in a material obtained from a composition containing a solvent-dispersed conductive polymer. Fig. 5 is a diagram schematically showing the mechanism of electrical conductivity development in a material obtained from a conductive composition according to one embodiment of the present invention.

[0010] In this specification, "x to y" represents a numerical range of "not less than x and not more than y." The upper and lower limits of the numerical ranges can be combined in any combination.

[0011] [Conductive Composition] The conductive composition according to one aspect of the present invention comprises: (a) carbon nanotubes (hereinafter also referred to as "component (a)"); (b) a soluble conductive polymer (hereinafter also referred to as "component (b)"); and (c) a solvent (hereinafter also referred to as "component (c)"). The soluble conductive polymer is either (i) or (ii) below: (i) a composite in which a conductive polymer is doped with a hydrophobic sulfonic acid compound; or (ii) a conductive polymer having a sulfonic acid group-containing side chain.

[0012] The conductive composition of this embodiment contains the above-mentioned components (a) to (c), and thus a material obtained from the conductive composition exhibits higher electrical and thermal conductivity than a material composed of carbon nanotubes alone (a material obtained from a carbon nanotube-containing composition without blending a conductive polymer). The reason for this is presumed to be as follows.

[0013] As shown in Fig. 1, in a material (e.g., a coating film, a molded body, etc.) obtained by removing the solvent component from a composition containing carbon nanotubes, the carbon nanotubes 10 come into contact with each other, and are electrically and thermally conductive at the contact points 10a, forming a conductive path (an electrically and thermally conductive region), thereby exhibiting electrical conductivity throughout the material (e.g., a coating film, a molded body, etc.) obtained after removing the solvent component. In the case of a material composed solely of carbon nanotubes, as shown in Fig. 2, the only electrically and thermally conductive path is formed at the contact points 10a where the carbon nanotubes 10 come into contact with each other.

[0014] On the other hand, Figure 3 is a schematic diagram showing a material obtained from a composition containing a solvent-dispersed conductive polymer and carbon nanotubes. Solvent-dispersed conductive polymers (e.g., poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS)) are generally dispersed in a solvent as particles of several tens of nanometers in size. Therefore, as shown in Figure 3 , even when a solvent-dispersed conductive polymer is mixed with carbon nanotubes (typical single-walled carbon nanotubes have a fiber diameter of 0.5 to 3 nm), the solvent-dispersed conductive polymer particles 12 only make point contact with the carbon nanotubes 10. Therefore, the only conductive paths between the carbon nanotubes 10 are formed at the contact points 10a between the carbon nanotubes 10 and between each carbon nanotube 10 and the conductive polymer particles 12. Therefore, even when a solvent-dispersed conductive polymer is mixed with carbon nanotubes, the increase in the conductive paths between the carbon nanotubes 10 is small, and the addition of the conductive polymer does not significantly improve electrical conductivity or thermal conductivity.

[0015] In contrast, in a material obtained by removing the solvent component from the conductive composition using the soluble conductive polymer of this embodiment, as shown in Figure 4, the soluble conductive polymer 11 adheres to the periphery, including the contact points between the carbon nanotubes 10, and coats a portion of the surface of the carbon nanotubes 10, or coats the entire surface of the carbon nanotubes 10. Therefore, in a material (e.g., a coating film, a molded product, etc.) obtained after removing the solvent component from the conductive composition of this embodiment, the carbon nanotubes 10 are electrically connected not only through the contact points and their periphery, but also through the soluble conductive polymer 11 present between each carbon nanotube 10. In other words, in the material obtained after removing the solvent component from the conductive composition of this embodiment, as shown in Figure 4, the conductive paths between the carbon nanotubes 10 are formed in a planar manner by the soluble conductive polymer 11 interposed between each carbon nanotube 10. Therefore, compared to the states shown in Figures 2 and 3, the conductive paths formed per unit volume are increased. Therefore, in the material obtained by removing the solvent component from the conductive composition of this embodiment, the contact resistance during electrical conduction is reduced compared to the states shown in Figures 2 and 3, and the overall resistance of the material after solvent removal is kept low, resulting in excellent electrical conductivity and excellent thermal conductivity. Note that a "soluble conductive polymer" refers to a conductive polymer that is soluble in a solvent component (organic solvent or water). A conductive polymer dissolved in a solvent component refers to a state in which the conductive polymer is dispersed in the solvent at the molecular level. Therefore, as shown in Figure 4, in the material obtained by removing the solvent component from the conductive composition containing the soluble conductive polymer, soluble conductive polymer 11 adheres to the periphery of carbon nanotubes 10, thereby coating the surface of each carbon nanotube 10, and it is believed that a planar conductive path is formed at the contact points between each carbon nanotube 10.

[0016] Furthermore, if a conductive polymer containing a hydrophilic dopant component (e.g., polystyrene sulfonate (PSS)) is used as the conductive polymer to be mixed with carbon nanotubes, or if a conductive polymer whose entire molecule is hydrophilic is used, it will have low affinity with the hydrophobic surface of the carbon nanotubes, making it difficult for the surface of each carbon nanotube to be entirely covered with the conductive polymer.

[0017] In contrast, the conductive composition of this embodiment uses, as the soluble conductive polymer, (i) a composite in which a conductive polymer is doped with a hydrophobic sulfonic acid compound, or (ii) a conductive polymer having a sulfonic acid group-containing side chain, which has a high affinity with the surface of hydrophobic carbon nanotubes. This affinity makes it easy for the soluble conductive polymer 11 to adhere to the periphery of each carbon nanotube 10, and after the solvent is removed, a state in which the surface of each carbon nanotube 10 is covered is obtained, which is presumably why a planar conductive path is formed between each carbon nanotube 10.

[0018] It is believed that the conductive composition of this embodiment can achieve high electrical conductivity and thermal conductivity that could not be achieved by conventional combinations of carbon nanotubes and conductive polymers due to the synergistic effect of the carbon nanotubes, which have high electrical and thermal conductivity, and the conductive polymer, which is both soluble and hydrophobic. Therefore, the conductive polymer used is not particularly limited as long as it is both soluble and hydrophobic, and can be used in the conductive composition of this embodiment, and the effects obtained by the conductive composition of this embodiment can be obtained.

[0019] Each component of the conductive composition of this embodiment will be described below.

[0020] (Component (a): Carbon Nanotubes) Examples of carbon nanotubes include single-walled carbon nanotubes (SWCNT), double-walled carbon nanotubes (DWCNT), multi-walled carbon nanotubes (MWCNT), carbon nanofibers, etc. As the carbon nanotubes, one of these may be used alone, or two or more may be used in combination.

[0021] The fiber diameter of the carbon nanotubes is not particularly limited. However, from the viewpoint of obtaining good conductivity in the material obtained from the conductive composition, for example, the fiber diameter of single-walled carbon nanotubes (SWCNTs) may be 0.1 to 50 nm, 0.3 to 10 nm, or 0.5 to 3 nm. The fiber diameter of multi-walled carbon nanotubes (MWCNTs) may be 1 to 500 nm, 3 to 300 nm, or 5 to 100 nm. The fiber diameter of double-walled carbon nanotubes (DWCNTs) may be 0.2 to 100 nm, 0.5 to 80 nm, or 1 to 50 nm. The fiber diameter of carbon nanofibers (CNFs) may be 100 to 1000 nm, 120 to 800 nm, or 150 to 500 nm. In this specification, the fiber diameter of carbon nanotubes refers to the outer diameter of the fiber. The fiber diameter and fiber length of carbon nanotubes, which will be described later, can be determined by observing the carbon nanotubes using a scanning transmission electron microscope, randomly selecting 100 carbon nanotubes from the observed image, measuring their outer diameters and lengths, and calculating the arithmetic mean values ​​of the outer diameters and the arithmetic mean values ​​of the lengths.

[0022] The fiber length of the carbon nanotubes is not particularly limited, but from the viewpoint of obtaining good conductivity in the 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.

[0023] The content of component (a) may be 5% by mass or more, 10% by mass or more, or 15% by mass or more, or may be 95% by mass or less, 93% by mass or less, 90% by mass or less, 80% by mass or less, or 70% by mass or less, relative to 100% by mass of the total of components (a) and (b). When the content of component (a) relative to 100% by mass of the total of components (a) and (b) is within the above range, good conductivity can be obtained in a material obtained from the conductive composition.

[0024] The content of component (a) may be, for example, 0.1% by mass or more, 0.15% by mass or more, or 0.18% by mass or more, relative to 100% by mass of the entire composition.

[0025] The carbon nanotubes can be used in the conductive composition of this embodiment in a state where they are dispersed in a dispersion medium. In this case, the dispersion medium for the carbon nanotubes is brought into the conductive composition of this embodiment and is contained in the solvent of component (c) in the conductive composition. The dispersion medium for the carbon nanotubes is not particularly limited as long as it can uniformly disperse the carbon nanotubes. However, preferred examples of the dispersion medium for the carbon nanotubes include glycol ethers such as dipropylene glycol dimethyl ether, methyl ethyl cellosolve, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate (PGMEA); ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and isophorone; alcohols such as methanol, ethanol, isopropyl alcohol, and ethylene glycol; N-methylpyrrolidone, N,N-dimethylformamide, and water.

[0026] (Component (b): Soluble Conductive Polymer) The soluble conductive polymer may be of the following (i) first type or (ii) second type: (i) a composite in which a conductive polymer is doped with a hydrophobic sulfonic acid compound; (ii) a conductive polymer having a sulfonic acid group-containing side chain;

[0027] (i) First Form The soluble conductive polymer of the first form is a composite in which a conductive polymer is doped with a hydrophobic sulfonic acid compound. The soluble conductive polymer of the first form described above exhibits 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 is covered with the soluble conductive polymer.

[0028] Examples of the conductive polymer of the first type include polyaniline, polythiophene, polypyrrole, and derivatives thereof. These may or may not have a substituent. These may be used alone or in combination of two or more.

[0029] As the conductive polymer, polyaniline is preferred from the viewpoints of versatility and economy. From the viewpoint of obtaining good conductivity in the composite, the polyaniline preferably has a weight-average molecular weight of 10,000 or more, more preferably 20,000 or more, even more preferably 30,000 or more and 1,000,000 or less, still more preferably 40,000 or more and 1,000,000 or less, and particularly preferably 52,000 or more and 1,000,000 or less.

[0030] The weight average molecular weight of polyaniline is measured by the method described in the examples.

[0031] The polyaniline may or may not have a substituent, but from the viewpoints of versatility and economy, unsubstituted polyaniline is preferred. When the polyaniline has a substituent, examples of the substituent include linear or branched hydrocarbon groups such as methyl, ethyl, hexyl, and octyl groups; alkoxy groups such as methoxy and ethoxy groups; aryloxy groups such as phenoxy groups; and trifluoromethyl groups (-CF ３ Examples of halogenated hydrocarbons include halogenated hydrocarbons such as aryl groups.

[0032] The hydrophobic sulfonic acid compound can be used without any particular limitation on its chemical structure, as long as it forms a complex that is soluble in a solvent when doped into a conductive polymer.

[0033] In this specification, "hydrophobic" refers to an HLB (Hydrophilic-Lipophilic Balance) value within the range of 1 to 8. Furthermore, if the number of carbon atoms in a sulfonic acid compound is 6 or more, the HLB value falls within the range of 1 to 8, and the sulfonic acid compound has hydrophobicity. In the following description, a hydrophobic sulfonic acid compound is also referred to as a hydrophobic sulfonic acid compound.

[0034] The hydrophobic sulfonic acid compound is doped into substituted or unsubstituted polyaniline as a proton donor to form a polyaniline composite. The doping of the hydrophobic sulfonic acid compound into polyaniline as a proton donor can be confirmed by ultraviolet, visible, and near-infrared spectroscopy or X-ray photoelectron spectroscopy. The sulfonic acid compound as a proton donor can be used without any particular chemical structural limitations as long as it has sufficient acidity to generate carriers in the polyaniline.

[0035] 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, and may be 35 or less, 30 or less, 25 or less, or 20 or less. When the number of carbon atoms in the hydrophobic sulfonic acid compound is within the above range, a composite in which a conductive polymer is doped with the hydrophobic sulfonic acid compound exhibits hydrophobicity as a whole and exhibits excellent solubility in a solvent (organic solvent or water).

[0036] 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. When the HLB value of the hydrophobic sulfonic acid compound is within the above range, a composite in which the hydrophobic sulfonic acid compound is doped into a conductive polymer exhibits hydrophobicity as a whole and exhibits excellent solubility in a solvent (organic solvent or water).

[0037] The HLB value of a sulfonic acid compound is calculated by the following formula based on the Griffin method: HLB value = 20 x sum of formula weights of hydrophilic moieties / molecular weight

[0038] Examples of the hydrophobic sulfonic acid compound (proton donor) include a sulfonic acid compound (proton donor) represented by the following formula (I): M(XAR ｎ ) ｍ (I) (In formula (I), M is a hydrogen atom, an organic free radical, or an inorganic free radical. X is —SO ３ － A is a hydrocarbon group which may contain a substituent. Each R is independently -R １ , -OR １ , -COR １ , -COOR １, -CO(COR １ ), or -CO(COOR １ ) is a substituent represented by R １ represents 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 or a group represented by -(OSiR ３ ２ ) ｘ -OR ３ (R ２ is an alkylene group, R ３ are hydrocarbon groups which may be the same or different, and x is an integer of 1 or more. n is an integer of 2 or more. m is the valence of M.

[0039] In the above formula (I), M is a hydrogen atom, an organic free radical, or an inorganic free radical. Examples of the organic free radical include a pyridinium group, an imidazolium group, and an anilinium group. Examples of the inorganic free radical include sodium, lithium, potassium, cesium, and ammonium.

[0040] A is a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group include a corresponding (n+1)-valent group such as a linear or branched alkyl group having 1 to 24 carbon atoms (preferably 1 to 8, more preferably 1 to 4 carbon atoms) (e.g., an ethylene group); an alkenyl group; a cycloalkyl group which may have a substituent such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, or menthyl; a dicycloalkyl or polycycloalkyl group which may be condensed, such as bicyclohexyl, norbornyl, or adamantyl; an aryl group containing an aromatic ring which may have a substituent such as phenyl, tosyl, thiophenyl, pyrrolinyl, pyridinyl, or furanyl; a diaryl or polyaryl group which may be condensed, such as naphthyl, anthracenyl, fluorenyl, 1,2,3,4-tetrahydronaphthyl, indanyl, quinolinyl, or indonyl; or an alkylaryl group.

[0041] Each R is independently -R １ , -OR１ , -COR １ , -COOR １ , -CO(COR １ ), or -CO(COOR １ ) is a substituent represented by R １ represents a hydrocarbon group having 4 or more carbon atoms (for example, 4 to 8 or 4 to 12) which may contain a substituent (for example, 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 or a group represented by -(OSiR ３ ２ ) ｘ -OR ３ (R ２ is an alkylene group, R ３ are hydrocarbon groups which may be the same or different, and x is an integer of 1 or more. １ Examples of the hydrocarbon group include a linear or branched butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a pentadecyl group, and an eicosanyl group. n is an integer of 2 or more (e.g., 2 to 4, or 2 to 3). m is the valence of M.

[0042] The sulfonic acid compound represented by the above formula (I) is hydrophobic, and a composite in which a conductive polymer is doped with the sulfonic acid compound exhibits excellent solubility in a solvent (organic solvent or water). Therefore, by using the sulfonic acid compound represented by formula (I) as a hydrophobic sulfonic acid compound, a state in which the surface of each carbon nanotube is coated with a soluble conductive polymer (a composite in which a conductive polymer is doped with the sulfonic acid compound of formula (I)) can be obtained.

[0043] The hydrophobic sulfonic acid compound (proton donor) represented by formula (I) is preferably a dialkylbenzenesulfonic acid, a dialkylnaphthalenesulfonic acid, a sulfophthalic acid ester, or a sulfonic acid compound (proton donor) represented by the following formula (II) (an organic protonic acid or a salt thereof): M(XCR ４ (CR ５２ COOR ６ ) COOR ７ ) ｐ (II)

[0044] In the above formula (II), M and X are the same as in formula (I), and p is the valence of M.

[0045] R ４ and R ５ are each independently a hydrogen atom, a hydrocarbon group, or R ８ ３ A group represented by Si— (where R ８ is a hydrocarbon group, and three R ８ may be the same or different). ４ and R ５ Examples of the hydrocarbon group of R include a linear or branched alkyl group having 1 to 24 carbon atoms, an aryl group containing an aromatic ring, and an alkylaryl group. ８ The hydrocarbon group of R ４ and R ５ The hydrocarbon group is the same as that of the above.

[0046] R ６ and R ７ are each independently a hydrocarbon group or -(R ９ O) ｑ -R １０ [wherein R ９ is a hydrocarbon group or a silylene group, and R １０ is a hydrogen atom, a hydrocarbon group, or R １１ ３ A group represented by Si- (R １１ is a hydrocarbon group, and three R １１ may be the same or different), and q is an integer of 1 or more. ６ and R ７ Examples of the hydrocarbon group include a linear or branched alkyl group having 1 to 24 carbon atoms, preferably 4 or more carbon atoms (for example, 4 to 10 or 4 to 14 carbon atoms); an aryl group containing an aromatic ring; and an alkylaryl group. ６ and R ７Specific examples of the hydrocarbon group include a linear or branched butyl group, a pentyl group, a hexyl group, an octyl group (for example, 2-ethylhexyl), a decyl group, and the like.

[0047] R ９ Examples of the hydrocarbon group include a linear or branched alkylene group having 1 to 24 carbon atoms, an arylene group containing an aromatic ring, an alkylarylene group, and an arylalkylene group. １０ and R １１ As the hydrocarbon group of R ４ and R ５ It is preferable that q is an integer of 1 to 10.

[0048] R ６ and R ７ Ga-(R ９ O) ｑ -R １０ When the proton donor represented by formula (II) is a group represented by the formula: (Wherein, X is —SO ３ and the like.)

[0049] The sulfonic acid compound represented by the above formula (II) is hydrophobic, and a composite in which the sulfonic acid compound is doped into a conductive polymer exhibits excellent solubility in a solvent (organic solvent or water). Therefore, by using the sulfonic acid compound represented by formula (II) as a hydrophobic sulfonic acid compound, a state in which the surface of each carbon nanotube is coated with a soluble conductive polymer (a composite in which the sulfonic acid compound of formula (II) is doped into a conductive polymer) can be obtained.

[0050] The hydrophobic sulfonic acid compound (proton donor) (organic protonic acid or its salt) represented by the above formula (II) is preferably a sulfosuccinic acid derivative represented by the following formula (III): M(O ３ SCH (CH ２ COOR １２ ) COOR １３ ) ｍ (III) In the above formula (III), M and m are the same as those in the above formula (I).

[0051] R １２ and R １３ are each independently a hydrocarbon group or -(R １４ O) ｒ -R １５ [wherein R １４ is a hydrocarbon group or a silylene group, and R １５ is a hydrogen atom, a hydrocarbon group, or R １６ ３ A group represented by Si— (where R １６ is a hydrocarbon group, and three R １６ may be the same or different), and r is an integer of 1 or more.

[0052] R １２ and R １３ The hydrocarbon group of R ６ and R ７ The hydrocarbon group is the same as that of R １４ The hydrocarbon group of R ９ The hydrocarbon group is the same as that of R １５ and R １６ The hydrocarbon group of R ４ and R ５ The hydrocarbon group is the same as the hydrocarbon group of the formula (1). r is preferably an integer of 1 to 10.

[0053] R １２ and R １３ But -(R １４ O) ｒ -R １５ Specific examples of the sulfosuccinic acid derivative represented by formula (III) are: ６ and R ７ Ga-(R ９ O) ｎ -R １０ The same applies to the proton donor represented by formula (II) when R is a group represented by formula (II). １２ and R １３ The hydrocarbon group of R ６ and R ７ The hydrocarbon groups are the same as those of the above, and preferred are butyl, hexyl, 2-ethylhexyl, decyl, and the like.

[0054] The sulfonic acid compound represented by the above formula (III) is hydrophobic, and a composite in which the sulfonic acid compound is doped into a conductive polymer exhibits excellent solubility in a solvent (organic solvent or water). Therefore, by using the sulfonic acid compound represented by formula (III) as a hydrophobic sulfonic acid compound, a state in which the surface of each carbon nanotube is coated with a soluble conductive polymer (a composite in which the sulfonic acid compound of formula (III) is doped into a conductive polymer) can be obtained.

[0055] As the hydrophobic sulfonic acid compound (proton donor), other than the sulfonic acid compounds (proton donors) represented by the above formulas (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.

[0056] When a hydrophobic sulfonic acid compound is used as a proton donor for polyaniline, the doping ratio of the hydrophobic sulfonic acid compound (proton donor) to polyaniline is preferably 0.30 to 0.65, more preferably 0.32 to 0.60, even more preferably 0.33 to 0.57, and particularly preferably 0.34 to 0.55. A doping ratio of 0.30 or higher ensures sufficient solubility of the polyaniline composite in organic solvents. The doping ratio is defined as (the number of moles of the hydrophobic sulfonic acid compound (proton donor) doped into the polyaniline) / (the number of moles of the polyaniline monomer unit). For example, a doping ratio 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 polyaniline monomer unit molecules. The doping ratio can be calculated by measuring the number of moles of the hydrophobic sulfonic acid compound (proton donor) and the polyaniline monomer unit in the polyaniline composite. In this embodiment, since the proton donor is an organic sulfonic acid, the number of moles of sulfur atoms derived from the proton donor and the number of moles of nitrogen atoms derived from the polyaniline monomer unit are quantified by organic elemental analysis, and the doping ratio can be calculated by calculating the ratio of these values.

[0057] The polyaniline composite preferably contains unsubstituted polyaniline and sulfonic acid as a proton donor, and satisfies the following formula (5): 0.32≦S ５ / N ５ ≦0.60 (5) (wherein, S ５ is the total number of moles of sulfur atoms contained in the polyaniline composite, and N ５ is the total number of moles of nitrogen atoms contained in the polyaniline composite. The number of moles of nitrogen atoms and sulfur atoms is a value measured by organic elemental analysis.

[0058] The soluble conductive polymer according to the first embodiment may be used alone or in combination of two or more.

[0059] The method for producing the soluble conductive polymer according to the first embodiment described above is not particularly limited, but for example, it can be produced by the method for producing the soluble conductive polymer according to the first embodiment described below.

[0060] For example, the above-mentioned hydrophobic sulfonic acid compound (proton donor), aniline corresponding to the above-mentioned polyaniline, and optionally a surfactant (e.g., a nonionic emulsifier) ​​are dissolved in a water-immiscible organic solvent (e.g., a hydrocarbon solvent (preferably toluene or xylene)), and an acidic aqueous solution (e.g., an aqueous phosphoric acid solution) is added thereto. The reaction solution, which has two liquid phases, the water-immiscible organic solvent and the water, is stirred, and a polymerization initiator (e.g., ammonium persulfate) is added to carry out polymerization. After polymerization, the water-immiscible organic solvent phase is separated by allowing the solution to stand, thereby obtaining a polyaniline complex water-immiscible organic solvent solution. This solution is transferred to an evaporator, and the volatiles are evaporated and distilled off to obtain a polyaniline complex (protonated polyaniline).

[0061] (ii) Second Form The soluble conductive polymer of the second form is a conductive polymer having a side chain containing a sulfonic acid group (sulfonic acid group-containing side chain). In the following description, a conductive polymer having a sulfonic acid group-containing side chain is also referred to as a sulfonic acid group-containing conductive polymer. The soluble conductive polymer of the second form described above exhibits high hydrophobicity and excellent solubility in solvents (organic solvents or water). Therefore, after removing the solvent contained in the conductive composition, the surface of each carbon nanotube is coated with the soluble conductive polymer.

[0062] Examples of the main chain monomer of the sulfonic acid group-containing conductive polymer include 3,4-ethylenedioxythiophene (EDOT), aniline, and methoxyaniline.

[0063] Examples of the sulfonic acid group-containing side chain covalently bonded to the main chain include an alkylsulfonic acid group, an alkyl ether sulfonic acid group, etc. The number of carbon atoms in the sulfonic acid group-containing side chain may be, for example, 1 to 15 or 2 to 10.

[0064] The content of 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, per 100 parts by mass of component (a). Furthermore, the content of component (b) may be 1 to 1000 parts by mass, 1 to 400 parts by mass, or 15 to 400 parts by mass, per 100 parts by mass of component (a). When the content of component (b) per 100 parts by mass of component (a) is within the above range, good conductivity can be obtained in a material obtained from the conductive composition.

[0065] The content of component (b) may be 0.01 to 20% by mass, 0.05 to 15% by mass, 0.08 to 10% by mass, or 0.15 to 10% by mass, relative to 100% by mass of the entire composition.

[0066] (Component (c): Solvent) The conductive composition according to one embodiment of the present invention contains a solvent. The solvent is not particularly limited as long as it dissolves component (b), and may be water or an organic solvent, but 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 that is substantially not miscible with water (a water-immiscible organic solvent). The solvent may contain a solvent that is brought into the conductive composition as a dispersion medium for component (a) carbon nanotubes. Furthermore, the solvent that dissolves component (b) and the dispersion medium for component (a) may be the same or different.

[0067] The water-soluble organic solvent may be a protic polar solvent or an aprotic polar solvent, and examples thereof include alcohols such as isopropyl alcohol, 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. In one embodiment, of the above water-soluble organic solvents, glycol ethers such as dipropylene glycol dimethyl ether and propylene glycol monomethyl ether acetate (PGMEA) are preferred. Examples of water-immiscible organic solvents include hydrocarbon solvents such as hexane, benzene, toluene, xylene, ethylbenzene, tetralin, and IP Solvent 1620; halogen-containing solvents such as methylene chloride, 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; and ether solvents such as cyclopentyl methyl ether, 4-methyltetrahydropyran, and 1,2-diethoxyethane. Furthermore, isoparaffin solvents containing one or more isoparaffins may be used as the hydrocarbon solvent.

[0068] Among these, toluene, xylene, methyl isobutyl ketone, chloroform, trichloroethane, ethyl acetate, tetrahydrofuran, cyclohexanone, and methyl ethyl ketone are preferred in terms of excellent solubility of component (b). Among component (b), the polyaniline composite can be dissolved even if the solvent is an alcohol such as isopropyl alcohol, 1-butanol, 2-butanol, 2-pentanol, benzyl alcohol, or an alkoxy alcohol. Alcohols are preferred from the viewpoint of reducing environmental impact compared to aromatic solvents such as toluene.

[0069] When an organic solvent is used as the solvent, a mixed organic solvent can be used in which a water-immiscible organic solvent and a water-soluble organic solvent are mixed in a mass ratio of 99 to 1:1 to 99. The use of a mixed organic solvent is preferred because it can prevent the generation of gels during storage and allows for long-term storage. A low-polarity organic solvent can be used as the water-immiscible organic solvent in the mixed organic solvent, and preferred low-polarity organic solvents are hydrocarbon solvents such as hexane and toluene; halogen-containing solvents such as chloroform; and isoparaffin-based solvents. As the water-soluble organic solvent of the mixed organic solvent, a highly polar organic solvent can be used, and examples thereof include alcohols such as methanol, ethanol, isopropyl alcohol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 3-methoxy-1-butanol, 1-ethoxy-2-propanol, 2-ethoxy-1-propanol, and 1-butoxy-2-propanol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and ethers such as tetrahydrofuran, diethyl ether, cyclopentyl methyl ether, 4-methyltetrahydropyran, and ethylene glycol mono-tert-butyl ether. The mixed organic solvent may contain one or more water-immiscible organic solvents, and may contain one or more water-soluble organic solvents.

[0070] The component (c) may be used alone or in combination of two or more.

[0071] The content of component (c) may be 50 to 99.8% by mass, 55 to 95% by mass, or 70 to 90% by mass, relative to 100% by mass of the entire composition.

[0072] (Component (d): Phenolic Compound) In one embodiment, the conductive composition further contains a phenolic compound in addition to the above-described components (a) to (c). By including a phenolic compound, the conductivity of a material obtained using the conductive composition can be further increased. 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). Specific examples include substituted phenols such as phenol, o-, m-, or p-cresol, o-, m-, or p-ethylphenol, o-, m-, or p-propylphenol, o-, m-, or p-butylphenol, o-, m-, or p-chlorophenol, o-, m-, or p-tert-amylphenol, salicylic acid, hydroxybenzoic acid, and hydroxynaphthalene; polyhydric phenolic compounds such as catechol and resorcinol; and polymeric compounds such as phenolic resins, polyphenols, and poly(hydroxystyrene).

[0073] Furthermore, a phenolic compound represented by the following formula (3) can be used. (In formula (3), n1 is an integer of 1 to 5 (preferably 1 to 3). R ２１ are each an alkyl group having 1 to 10 carbon atoms (preferably 2 to 8, more preferably 3 to 7), an alkenyl group having 2 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 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.

[0074] The above R ２１The following will explain the above. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, and tert-amyl. Examples of alkenyl groups include the above-mentioned alkyl group substituents having an unsaturated bond in the molecule. Examples of cycloalkyl groups include cyclopentane and cyclohexane. Examples of alkylthio groups include methylthio and ethylthio. Examples of aryl groups include phenyl and naphthyl. Examples of alkylaryl groups and arylalkyl groups include substituents obtained by combining the above-mentioned alkyl and aryl groups. Of these groups, R ２１ As the aryl group, a methyl or ethyl group is preferred.

[0075] Furthermore, a phenolic compound represented by the following formula (3') can be used. (In formula (3'), R ２２ 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.) R in formula (3') ２２ Specific examples of R in the above formula (3) ２１ is the same as:

[0076] The component (d) may be used alone or in combination of two or more.

[0077] 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%, relative to 100 mass% of the entire conductive composition.

[0078] (Component (e): Acidic Substance and / or Salt of Acidic Substance) In one embodiment, in addition to the above-described components (a) to (c), the conductive composition may further contain an acid species different from the above-described hydrophobic sulfonic acid compound (proton donor), and may further contain one or more selected from the group consisting of acidic substances and salts of acidic substances (hereinafter also referred to as "component (e)"). This component is usually used as a heat resistance stabilizer, and can further improve the heat resistance of conductive materials such as conductive films obtained using the conductive composition. Component (e) may be added to the conductive composition, or may be incorporated into a coating film or the like formed from the conductive composition by immersing it in a solution in which an acidic substance and / or a salt of an acidic substance is dissolved.

[0079] The acidic substance may be either an organic acid, which is an acid of an organic compound, or 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.

[0080] The organic acid having a sulfonic acid group is preferably a cyclic, linear, or branched alkylsulfonic acid, a substituted or unsubstituted aromatic sulfonic acid, or a polysulfonic acid having one or more sulfonic acid groups. Examples of the alkylsulfonic acid include methanesulfonic acid and ethanesulfonic acid. Here, the alkyl group is preferably a linear or branched alkyl group having 1 to 18 carbon atoms. Examples of the aromatic sulfonic acid include those 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.

[0081] The substituent is, for example, a substituent selected from the group consisting of an alkyl group (e.g., one having 1 to 20 carbon atoms), an alkoxy group (e.g., one having 1 to 20 carbon atoms), a hydroxy group, a nitro group, a carboxy group, and an acyl group, and one or more of these may be substituted.

[0082] Specific examples of aromatic sulfonic acids include compounds represented by the following formula (4) or (5). (In formula (4), l is 1 or more, m is an integer of 0 to 5, and n is an integer of 0 to 5. When either m or n is 0, the other is 1 or more.) (In formula (5), q is 1 or more, p is an integer of 0 to 7, and each R is independently an alkyl group having 1 to 20 carbon atoms, a carboxy group, a hydroxyl group, a nitro group, a cyano group, or an amino group.)

[0083] In formula (4), l is preferably 1 to 3. In formula (4), m is preferably 1 to 3. In formula (4), n is preferably 0 to 3. In formula (5), q is preferably 1 to 3. In formula (5), p is preferably 0 to 3. In formula (5), R is preferably an alkyl group having 1 to 20 carbon atoms, a carboxy group, or a hydroxyl group.

[0084] Examples of aromatic sulfonic acids 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 these, from the viewpoint of improving heat resistance, 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.

[0085] Examples of salts of acidic substances include salts of the compounds listed above. Counter ions of the salts include sodium, lithium, potassium, cesium, ammonium, calcium, barium, etc. Component (e) may be a hydrate.

[0086] The component (e) may be used alone or in combination of two or more.

[0087] When component (e) is contained, the content of component (e) is preferably 0.01 to 10 mass%, more preferably 0.02 to 5 mass%, and even more preferably 0.05 to 3 mass%, relative to 100 mass% of the total composition.

[0088] When component (e) is contained, the mass ratio of the content of component (b) to the content of component (e) (“content of component (b)”: “content of component (e)”) may 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, from the viewpoint of heat resistance.

[0089] In one embodiment, the conductive composition may contain various additives such as a binder in addition to the above-described components (a) to (e). Known binders can be used. In one embodiment, the conductive composition may further contain at least one selected from the group consisting of a resin and an inorganic material in addition to the above-described components (a) to (e). Known resins and inorganic materials used to obtain molded articles containing carbon nanotubes can be used without any particular limitation. In one embodiment, the conductive composition may contain various additives such as a binder in addition to the above-described components (a) to (e), and may also contain at least one selected from the group consisting of a resin and an inorganic material.

[0090] A composition according to one embodiment of the present invention may consist essentially of one or more components selected from the group consisting of components (a), (b), and (c), and optionally components (d) and (e). In this case, other inevitable impurities may be contained as long as the effects of the present invention are not impaired. 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 according to one embodiment of the present invention may consist of components (a) to (c), components (a) to (d), components (a) to (c), and (e), or components (a) to (e).

[0091] The method for preparing the composition according to one embodiment of the present invention is not particularly limited, and the composition can be obtained by mixing the aforementioned components (a) to (e) by a known method. The mixing method is not particularly limited, and for example, the composition can be prepared by stirring and mixing a mixed solution containing the aforementioned components (a) to (e) by a known method, and the stirring temperature and stirring speed are not particularly limited. The order of mixing is also not particularly limited, and for example, component (a) may be added to a solution obtained by adding component (b) to a mixed solvent containing components (c) to (e), and then the solution may be stirred and mixed, or component (b) may be added to a solution obtained by adding component (a) to a mixed solvent, and then the solution may be stirred and mixed.

[0092] [Conductive Film] A conductive film according to one aspect of the present invention is a conductive film comprising: (a) carbon nanotubes; and (b) a soluble conductive polymer, wherein the soluble conductive polymer is either (i) or (ii) below: (i) a composite in which a conductive polymer is doped with a hydrophobic sulfonic acid compound; or (ii) a conductive polymer having a sulfonic acid group-containing side chain.

[0093] The conductive film according to one embodiment of the present invention is formed using the conductive composition described above. For example, the conductive film can be formed by applying the conductive composition according to one embodiment of the present invention to a substrate and drying it to remove component (c) (solvent). The conductive composition may be applied to a substrate such as glass, a resin film, a sheet, or a nonwoven fabric having a desired shape to form a conductive laminate. The thickness of the conductive film is usually 1 mm or less, preferably 10 nm to 50 μm.

[0094] The surface resistance of the conductive film according to one embodiment of the present invention may be, for example, 500 Ω / □ or less, 450 Ω / □ or less, 400 Ω / □ or less, 300 Ω / □ or less, 200 Ω / □ or less, or 150 Ω / □ or less, from the viewpoint of exerting the effect as a conductive material. The surface resistance of the conductive film is measured by the method described in the examples.

[0095] The composition can be applied by any known method such as casting, spraying, dip coating, doctor blade, bar code printing, spin coating, electrospinning, screen printing, or gravure printing.

[0096] In addition, a step of immersing the conductive film (coating film) in a solution containing the component (e) and drying it may be provided. In this case, the component (e) is preferably a compound represented by the formula (4) or a salt thereof.

[0097] The solution used for immersion may contain a solvent. The solvent is not particularly limited as long as it dissolves component (e), and examples thereof include water, alcohol-based solvents, ketone-based solvents, ether-based solvents, and ester-based solvents. One or more types of solvents may be used in combination.

[0098] 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.

[0099] The content of component (e) in the solution used 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, per part by mass of the composition obtained after removing the solvent. If the content exceeds 1200 parts by mass, the acidic substance will be excessive in the coating film, which may cause deterioration of the polyaniline main chain and reduce the conductivity.

[0100] The content of component (e) in the solution used 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.

[0101] The immersion method may be dipping. The immersion time is preferably 1 minute or more, more preferably 3 minutes to 200 minutes, and even more preferably 7 minutes to 30 minutes. The immersion temperature is preferably 5°C to 50°C. Drying after immersion is preferably carried out using an oven, a hot plate, or the like. The drying temperature is preferably 80 to 200°C, more preferably 100 to 170°C. The drying time is preferably 1 to 180 minutes, more preferably 3 to 60 minutes. Heating under reduced pressure may be performed as necessary. The drying temperature and drying time are not particularly limited and may be selected appropriately depending on the material used.

[0102] As described above, component (e) may be added to the conductive composition or may be contained in a conductive film obtained from the conductive composition. Component (e) may be added to a conductive composition, and then component (e) may be contained in a conductive film obtained from the conductive composition. That is, a conductive film according to one embodiment of the present invention may contain component (e) (hereinafter sometimes referred to as component (e1)) added to the composition before film formation and component (e) (hereinafter sometimes referred to as component (e2)) added by immersion after film formation. Components (e1) and (e2) may be the same or different. When they are different, for example, component (e1) is a compound represented by formula (5) above, and component (e2) is a compound represented by formula (4) above.

[0103] The conductive film according to one embodiment of the present invention can be used as a battery material.

[0104] [Conductive Laminate] A conductive laminate according to one embodiment of the present invention includes a substrate and a conductive layer made of the conductive material according to one embodiment of the present invention, with the conductive layer being in contact with the substrate. For example, a conductive laminate having a conductive layer (conductive film) can be produced by applying the conductive composition according to 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 article can be produced by processing the conductive laminate into a desired shape using a known method such as vacuum forming or pressure forming. From the viewpoint of molding, the substrate is preferably a resin film, a sheet, or a nonwoven fabric.

[0105] The conductive composition can be applied to a substrate by known methods such as casting, spraying, dip coating, doctor blade coating, bar coating, spin coating, electrospinning, screen printing, and gravure printing. When drying the coating film, the coating film may be heated depending on the type of solvent. For example, the coating film is heated at a temperature of 250°C or less, preferably 50 to 200°C, in an air stream, and further heated under reduced pressure or in a nitrogen stream, as necessary. The heating temperature and heating time are not particularly limited and may be appropriately selected depending on the material used.

[0106] The composition according to one aspect of the present invention can also be used to form a self-supporting molded article that does not have a substrate.

[0107] [Conductive Material] 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. The conductive material according to one embodiment of the present invention is obtained, for example, by removing component (c) (solvent) from the conductive composition according to one embodiment of the present invention. For example, a method for removing component (c) (solvent) can be exemplified by applying the conductive composition to a substrate and drying it. The film, molded body, powder, or granules according to one embodiment of the present invention include the conductive material according to one embodiment of the present invention. In other words, the shape of the conductive material according to one embodiment of the present invention is not particularly limited and can be selected according to the purpose, and examples thereof include a film, molded body, powder, granules, etc.

[0108] The conductive material according to one embodiment of the present invention can be used, for example, as a conductive additive for a battery. The conductive additive for a battery may be in the form of a film, powder, or granules.

[0109] [Conductive Article] A conductive article according to one embodiment of the present invention is made from a mixture of the conductive composition according to one embodiment of the present invention and at least one selected from the group consisting of a resin and an inorganic material. The conductive article according to one embodiment of the present invention can be obtained by mixing the conductive composition according to one embodiment of the present invention with at least one selected from the group consisting of a resin and an inorganic material, and then, for example, drying the mixture to remove component (c) (solvent). The shape of the conductive article is not particularly limited and can be determined appropriately depending on the intended use.

[0110] [Battery] A battery according to an embodiment of the present invention includes a conductive additive for a battery containing the conductive material according to an embodiment of the present invention. The battery is not particularly limited, but examples thereof include lithium secondary batteries.

[0111] Production Example 1 (Production of Polyaniline Composite) 32.4 g of "Neocol SWC" (di-2-ethylhexyl sodium sulfosuccinate, manufactured by Dai-ichi 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 placed in a 1,000 mL separable flask and dissolved in 320.4 g of toluene. 450 g of an 8.5 wt % aqueous phosphoric acid solution was added thereto, and the reaction solution, which had two liquid phases of toluene and water, was stirred and cooled to an internal temperature of 5°C. When the internal temperature of the reaction solution reached 5°C, a solution of 39.3 g of APS (ammonium persulfate) dissolved in 90.2 g of an 8.5 wt % aqueous phosphoric acid solution was added using a dropping funnel while stirring the reaction solution, and the solution was stirred for 4 hours while maintaining the internal temperature at 5°C. After stopping the stirring, the contents were transferred to a separatory funnel, and the aqueous phase and toluene phase (organic phase) were allowed to stand and separated. After separation, the toluene phase (organic layer) was washed once with 180.3 g of an 8.5 wt% aqueous phosphoric acid solution and five times with 328.0 g of ion-exchanged water to obtain a polyaniline complex toluene solution. This solution was transferred to an evaporator, heated in a 60°C water bath, and reduced pressure to evaporate and remove volatiles, yielding a polyaniline complex (protonated polyaniline). The weight-average molecular weight (Mw) of the polyaniline in Polyaniline Complex 1 was 73,000.

[0112] The weight-average molecular weight of polyaniline was measured as follows. 1.65 to 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 this 0.01 M lithium bromide NMP solution, and the mixture was stirred and dissolved to obtain a homogeneous solution. 50 μL of the polyaniline composite toluene solution obtained in Production Example 1 was then added dropwise, stirred and mixed, and passed through a 0.45 μm filter to prepare a sample for gel permeation chromatography (GPC) measurement. GPC measurement was performed using two connected GPC columns (Shodex KF-806M, manufactured by Showa Denko K.K.) under the following measurement conditions. Solvent: NMP containing 0.01 M LiBr Flow rate: 0.70 mL / min Column temperature: 60° C. Injection volume: 100 μL UV detection wavelength: 270 nm The weight average molecular weight obtained by the above method is a polystyrene (PS) equivalent value.

[0113] The doping ratio of the proton donor (sodium di-2-ethylhexyl sulfosuccinate) to the polyaniline was 0.36.

[0114] The HBL value of "Neocol SWC" (di-2-ethylhexyl sodium sulfosuccinate, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was calculated based on the following formula (A): HBL value = 20 × (SO ３ Formula weight of Na part) / Molecular weight (A)

[0115] Sodium di-2-ethylhexyl sulfosuccinate (molecular weight: 443.61, SO ３ The HLB value based on formula (A) of the sodium hydroxide (formula weight of the sodium part: 81.07) is: Formula (A) = 20 × 81.07 / 443.61 = 3.66.

[0116] Example 1 (Preparation of Conductive Composition) 70 g of cyclohexanone (component (c)) (manufactured by Tokyo Chemical Industry Co., Ltd.) and 30 g of 4-tert-amylphenol (component (d)) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were mixed until homogeneous to prepare mixed solution A. 1.6 g of the polyaniline composite (component (b)) obtained in Production Example 1 was dissolved in 98.4 g of mixed solution A to obtain polyaniline solution A (polyaniline composite concentration: 1.6 mass %). 2 g of a dispersion of single-walled carbon nanotubes (SWCNT) (component (a)), 0.05 g of polyaniline solution A, and 1.95 g of mixed solution A were mixed with stirring to obtain a conductive composition (CNT / polyaniline composite-containing solution). The blending ratios of each component contained in the single-walled carbon nanotube (SWCNT) dispersion are shown below. Carbon nanotubes (SWCNT): 0.4% by mass Alkylacetalized polyvinyl alcohol: 1.0% by mass Propylene glycol monomethyl ether acetate (PGMEA): 98.6% by mass

[0117] (Evaluation of Conductive Film (Surface Resistance)) The conductive composition (CNT / polyaniline composite-containing solution) obtained in Example 1 was applied to an easily adhesive PET substrate using a bar coater under the following conditions, followed by drying to obtain a conductive film (CNT / polyaniline composite film). Bar coating conditions Coating device: Mini Coater "MC30" (manufactured by Hosen Co., Ltd.) Coating speed: 30 mm / s Applicator spacing: 150 μm Drying conditions: 150°C, 10 min The surface resistance of the conductive film (CNT / polyaniline composite film) obtained above was measured using a four-terminal resistivity meter "Loresta GP" (manufactured by Mitsubishi Chemical Corporation). The measurement results are shown in Table 1. The thickness of the conductive film was measured using a linear gauge sensor (manufactured by Ono Sokki Co., Ltd.). The thickness of the conductive film is shown in Table 1.

[0118] Examples 2 to 5, Comparative Example 1 Conductive compositions (CNT / polyaniline composite-containing solutions) were obtained in the same manner as in Example 1, except that the blending ratios of the same 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. Conductive films (CNT / polyaniline composite films) were produced and evaluated in the same manner as in Example 1, except that the conductive compositions (CNT / polyaniline composite-containing solutions) used in Examples 2 to 5 and Comparative Example 1 were used instead of the conductive composition used in Example 1. The measurement results of the film thickness and surface resistance of each conductive film are shown in Table 1.

[0119]

[0120] In Table 1, "CHN" represents cyclohexanone, and "tAP" represents 4-tert-amylphenol. In Table 1 and Table 2 described later, "E+XX" represents "×10 ＸＸ " means.

[0121] Example 6 (Preparation of Composition) 70 g of tetrahydrofuran (component (c)) (manufactured by Tokyo Chemical Industry Co., Ltd.) and 30 g of 4-tert-amylphenol (component (d)) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were mixed until homogeneous to prepare mixed solution B. 0.4 g of the polyaniline composite (component (b)) obtained in Production Example 1 was dissolved in 99.6 g of mixed solution B to obtain polyaniline solution B (polyaniline composite concentration: 0.4 mass%). 2 g of the same single-walled carbon nanotube (SWCNT) dispersion (component (a)) (single-walled carbon nanotube concentration 0.4 mass%) used in Example 1 and 2 g of polyaniline solution B were mixed and stirred to obtain a conductive composition (CNT / polyaniline composite-containing solution).

[0122] (Evaluation of Conductive Film (Surface Resistance)) The conductive composition (CNT / polyaniline composite-containing solution) 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 (CNT / polyaniline composite film). Spin coating conditions Coating device: Spin coater "MS-A100" (manufactured by Mikasa Co., Ltd.) Rotation speed: 500 rpm Drying conditions: 150°C, 5 min The surface resistance of the conductive film (CNT / polyaniline composite film) obtained above was measured using a four-terminal resistivity meter "Loresta GP" (manufactured by Mitsubishi Chemical Corporation). The results are shown in Table 2. The film thickness of the conductive film was measured using a linear gauge sensor (manufactured by Ono Sokki Co., Ltd.). The film thickness of the conductive film is shown in Table 2.

[0123] Example 7 0.4 g of the polyaniline composite obtained in Production Example 1 was dissolved in 99.6 g of tetrahydrofuran to obtain polyaniline solution C (polyaniline composite concentration: 0.4 mass %). The subsequent steps were the same as in Example 6, except that polyaniline solution B in Example 6 was replaced with polyaniline solution C, to obtain a conductive composition (CNT / polyaniline composite-containing solution). A conductive film (CNT / polyaniline composite film) was produced and evaluated in the same manner as in Example 6, except that the conductive composition of Example 7 (CNT / polyaniline composite-containing solution) was used instead of the conductive composition of Example 6. The measurement results of the film thickness and surface resistance of the conductive film are shown in Table 2.

[0124] Comparative Example 2 2 g of the same single-walled carbon nanotube (SWCNT) dispersion liquid (carbon nanotube concentration 0.4% by mass) used in Example 1 and 2 g of tetrahydrofuran (component (c)) (manufactured by Tokyo Chemical Industry Co., Ltd.) were mixed to obtain a conductive composition (CNT dispersion liquid). A conductive film (film of CNT alone) was produced and evaluated in the same manner as in Example 6, except that the conductive composition (CNT dispersion liquid) of Comparative Example 2 was used instead of the conductive composition of Example 6. The measurement results of the film thickness and surface resistance of the conductive film are shown in Table 2.

[0125]

[0126] In Table 2, "THF" represents tetrahydrofuran, and "tAP" represents 4-tert-amylphenol.

[0127] As shown in Tables 1 and 2, the conductive films obtained from the conductive compositions of Examples 1 to 7, in which the polyaniline complex was blended with the carbon nanotubes, had lower surface resistance values ​​than those of Comparative Examples 1 and 2, in which only the carbon nanotubes were used, and excellent conductivity was obtained. Furthermore, the surface resistance of the obtained conductive film decreased with an increase in the blending amount of the polyaniline complex, and the conductive film of Example 5, which had the highest blending amount of the polyaniline complex, showed a significantly lower surface resistance than the conductive film of Example 1.

[0128] The conductive composition of the present invention and the conductive film of the present invention can be used as a conductive assistant, an electrode for a touch screen film, an electromagnetic wave shielding material, an antistatic agent, a battery, a capacitor, etc.

[0129] Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will readily be able to make numerous modifications to these exemplary embodiments and / or examples without substantially departing from the novel teachings and advantages of the present invention. Accordingly, these numerous modifications are within the scope of the present invention. The contents of all documents cited in this specification and of the applications from which this application claims priority under the Paris Convention are incorporated by reference in their entirety.

Claims

1. (a) Carbon nanotubes, (b) Soluble conductive polymers, and (c) solvent Includes, A conductive composition wherein the soluble conductive polymer is (i) or (ii) below. (i) Composites of conductive polymers doped with hydrophobic sulfonic acid compounds (ii) Conductive polymer having sulfonic acid group-containing side chains

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 (i) is 1 to 8.

4. The conductive composition according to claim 1 or 2, wherein the hydrophobic sulfonic acid compound in (i) is a sulfonic acid compound represented by the following formula (III). M(O ３ SCH(CH ２ COOR １２ )COOR １３ ) ｍ (III) (In equation (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 are each independently a hydrocarbon group or -(R １４ O) ｒ -R １５ a group represented by, R １４ is a hydrocarbon group or a silylene group, R １５ is a hydrogen atom, hydrocarbon group or R １６ ３ It is a group represented by Si-, R １６ It is a hydrocarbon group, and has three R １６ (These may be the same or different, and r is an integer greater than or equal to 1.)

5. The conductive composition according to claim 1 or 2, wherein the conductive polymer in (i) is polyaniline.

6. The conductive composition according to claim 1 or 2, further comprising (d) a phenolic compound.

7. The conductive composition according to claim 1 or 2, wherein the content of component (b) is 1 to 400 parts by mass per 100 parts by mass of component (a).

8. Furthermore, the conductive composition according to claim 1 or 2, comprising at least one selected from the group consisting of resins and inorganic materials.

9. A conductive material made from the conductive composition described in claim 1 or 2.

10. A film, molded article, powder, or granules comprising the conductive material described in claim 9.

11. A conductive additive for batteries, comprising the conductive material described in claim 9.

12. (a) Carbon nanotubes, and (b) Soluble conductive polymer A conductive film containing, A conductive film wherein the soluble conductive polymer is (i) or (ii) below. (i) Composites of conductive polymers doped with hydrophobic sulfonic acid compounds (ii) Conductive polymer having sulfonic acid group-containing side chains

13. A conductive article made from a mixture of the conductive composition according to claim 1 or 2 and at least one selected from the group consisting of resins and inorganic materials.

14. Substrate and A conductive layer made of the conductive material described in claim 9, The conductive layer and the substrate are in contact. Conductive laminate.

15. A battery comprising the conductive additive for batteries described in claim 11.