Conductive material dispersion

Abstract

The present invention relates to an electrically conductive material dispersion including single-walled carbon nanotubes, a dispersant, a dispersion aid, and a dispersion medium, wherein the dispersant includes polyvinyl butyral and hydrogenated nitrile rubber, and the dispersion aid includes a compound represented by Formula 1.[Formula 1]A-(R) n In Formula 1, A is a structure having 16 to 50 carbons and including four or more aromatic rings and nitrogen, R is a structure including an anionic functional group, and n is an integer of 1 to 5.

Description

TECHNICAL FIELD

[0001] The present application relates to a conductive material dispersion including single-walled carbon nanotubes, a dispersant, a dispersing aid, and a dispersion medium, in which the dispersant includes polyvinyl butyral and hydrogenated nitrile rubber, and the dispersing aid includes a specific compound. BACKGROUND

[0002] Due to the rapid increase in the use of fossil fuels, the demand for the use of alternative or clean energy is increasing, and as part of this demand, the most active research area includes the field of power generation and energy storage using electrochemical reactions.

[0003] Recently, as a typical example of an electrochemical device using such an electrochemical energy, a secondary battery can be included, and the field of use is gradually expanding. Recently, as technology has developed and the demand for portable computers, mobile phones, cameras, and the like has increased, the demand for secondary batteries as energy sources has rapidly increased, and among these secondary batteries, much research has been conducted on lithium secondary batteries having high energy density, that is, high capacity, and their commercialized products are widely used.

[0004] The positive electrode of the secondary battery includes a positive active material, a conductive material, and a binder. In order to improve the conductivity of the positive electrode, carbon nanotubes can be used as the conductive material. If single-walled carbon nanotubes are used instead of multi-walled carbon nanotubes as the carbon nanotubes, there is an effect of further reducing the resistance of the electrode. In order to uniformly distribute the single-walled carbon nanotubes in the positive electrode, a conductive material dispersion in which the single-walled carbon nanotubes are dispersed is first formed, and the positive electrode slurry is prepared using the conductive material dispersion during the manufacture of the positive electrode.

[0005] In order to prepare the conductive material dispersion, a high-pressure homogenizer is used. Specifically, in the high-pressure homogenizer, a pre-mixing solution including bundle-type single-walled carbon nanotubes, a dispersant, and a dispersion medium passes through a nozzle having a diameter of 150 micrometers at a high pressure of 1,500 bars, and thereby a shearing force is applied to the bundle-type single-walled carbon nanotubes, dispersing the bundle-type single-walled carbon nanotubes.

[0006] Meanwhile, in a pre-mixing state of a solution including bundle-type single-walled carbon nanotubes, a dispersant, and a dispersion medium, the bundle-type single-walled carbon nanotubes in the solution need to be effectively de-bundled by the dispersant, and thus a dispersion process using a high-pressure homogenizer is possible, and a conductive material dispersion in which single-walled carbon nanotubes are uniformly dispersed is finally prepared. In contrast, if de-bundling is not smooth during pre-mixing, phase separation occurs between the bundle-type carbon nanotubes in the solution and the dispersion medium, and a nozzle of the high-pressure homogenizer can be clogged with the bundle-type carbon nanotubes, and thus the dispersion process using the high-pressure homogenizer is not possible. In addition, in order to improve the manufacturing yield of the positive electrode, it is advantageous to increase the solid content of the conductive material dispersion, but as the solid content of the conductive material dispersion increases, the problem that the high-pressure homogenizer cannot be used can become more serious.

[0007] In addition, although the high-pressure homogenizer can be used, if the viscosity of the conductive material dispersion having the same solid content is too high, the conductive material dispersion can not be smoothly transported, the flowability of the positive electrode slurry prepared from the conductive material dispersion can be reduced, and the manufacturing processability of the positive electrode can be degraded.

[0008] In order to solve these problems, conventionally, a method of including a dispersant such as hydrogenated nitrile rubber and polyvinylidene fluoride in the conductive material dispersion has been used. However, in the case of using the conventional general dispersant, the improvement effect of de-bundling is not significant, and in particular, if the solid content of the conductive material dispersion is high, it is not much effective. SUMMARY

[0009] Technical problem

[0010] The task to be achieved by the present application is to provide a conductive material dispersion which can be applied to a dispersion process using a high-pressure homogenizer and has a low viscosity level among conductive material dispersions having the same solid content.

[0011] Technical solution

[0012] According to one embodiment of the present application, the present application provides a conductive material dispersion including single-walled carbon nanotubes, a dispersant, a dispersion aid, and a dispersion medium, in which the dispersant includes polyvinyl butyral and hydrogenated nitrile rubber, and the dispersion aid includes a compound represented by Formula 1.

[0013] [Formula 1]

[0014] A-(R) n

[0015] In Formula 1, A is a structure having 16 to 50 carbons and including four or more aromatic rings and nitrogen, R is a structure including an anionic functional group, and n is an integer of 1 to 5.

[0016] Beneficial effects

[0017] According to the present application, in the process of preparing the conductive material dispersion, the bundled single-walled carbon nanotubes can be effectively unbundled after pre-mixing, and the conductive material dispersion can be prepared by a high-pressure homogenizer, and accordingly, the single-walled carbon nanotubes can be effectively dispersed in the conductive material dispersion in the conductive material dispersion having the same solid content. In addition, the dispersion is possible despite the solid content of the conductive material dispersion being at a high level, and the electrode manufacturing yield can be improved due to the high solid content of the conductive material dispersion. In addition, the viscosity of the conductive material dispersion can be at a low level, the transport of the conductive material dispersion can become smooth, and the manufacturing processability of the positive electrode can be greatly improved. DETAILED DESCRIPTION

[0018] Hereinafter, the present application will be explained in more detail to help understanding of the present application.

[0019] It will be understood that the words or terminology used herein in the specification and the claims is not intended to be construed as having a meaning defined in commonly used dictionaries. It will be further understood that the meaning of the words or terminology used herein should be interpreted based on the meaning of the words or terminology in the context of the relevant art and the principles of the present application.

[0020] The terminology used in the specification will be solely for the purpose of explaining exemplary embodiments and is not intended to limit the present application. The singular forms are intended to include the plural forms unless the context clearly indicates otherwise.

[0021] It will be further understood that the terms "comprises", "comprising", "includes" and / or "including", as used herein, specify the presence of stated features, integers, steps, elements, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, elements, or combinations thereof.

[0022] In the present specification, D 50 may be defined as a particle diameter corresponding to 50% of a volume accumulation on a particle diameter distribution curve. D50may be measured by using, for example, a laser diffraction method. 50Laser diffraction can typically measure diameters from the submicron level to several millimeters, yielding results with high reproducibility and high resolution. The instrument used for the measurement was the Malvern Co. Mastersizer 3000, which measures D... 50 Three times, the average is considered as the final D 50 .

[0023] In this manual, a TOKI Co. viscometer TV-22 was used to measure viscosity at 25°C and 1 rpm.

[0024] <Conductive Material Dispersion>

[0025] According to one embodiment of the present invention, a conductive material dispersion comprises single-walled carbon nanotubes, a dispersant, a dispersing aid, and a dispersion medium, wherein the dispersant comprises polyvinyl butyral and hydrogenated nitrile rubber, and the dispersing aid comprises compounds represented by Formula 1.

[0026] [Formula 1]

[0027] A-(R) n

[0028] In Formula 1, A is a structure having 16 to 50 carbon atoms and including four or more aromatic rings and nitrogen, R is a structure including anionic functional groups, and n is an integer from 1 to 5. The conductive material dispersion may correspond to a conductive material dispersion used in the manufacture of secondary battery electrodes.

[0029] Single-walled carbon nanotubes have a cylindrical fullerene series structure, which refers to a long and hollow tubular carbon structure with a membrane composed of a single layer of carbon atoms as the wall.

[0030] D of single-walled carbon nanotubes 50 The diameter can range from 0.4 μm to 100 μm, specifically from 1 μm to 50 μm, more specifically from 1 μm to 30 μm, for example from 1 μm to 10 μm. This is related to the D-type single-walled carbon nanotubes used as raw materials for preparing conductive material dispersions. 50 Compared to the 200 μm level, the D of single-walled carbon nanotubes 50 The fact that the diameter ranges from 1 μm to 100 μm implies that the bundled carbon nanotubes are partially unbundled, and that after applying a high-pressure homogenizer, the bundled single-walled carbon nanotubes are dispersed and exist within the conductive material dispersion. Furthermore, if D 50 As the size decreases, single-walled carbon nanotubes will be uniformly dispersed in a conductive material dispersion with the same solid content.

[0031] The single-walled carbon nanotubes can be included in the conductive material dispersion at 0.01 to 5% by weight, specifically 0.01 to 1% by weight, more specifically 0.05 to 0.8% by weight, for example, 0.1 to 0.6% by weight.

[0032] The dispersant functions to smoothly disperse the single-walled carbon nanotubes in the conductive material dispersion, to have a preferred particle size, so that the single-walled carbon nanotubes are uniformly dispersed and present in the conductive material dispersion.

[0033] The dispersant can be included at 10 to 2,000 parts by weight, specifically 10 to 1,000 parts by weight, more specifically 30 to 500 parts by weight, based on 100 parts by weight of the single-walled carbon nanotubes. If the above range is satisfied, the single-walled carbon nanotubes can be smoothly dispersed, the single-walled carbon nanotubes can have a small particle size value, and the viscosity of the conductive material dispersion can be controlled at an appropriate level.

[0034] The dispersant can include polyvinyl butyral and hydrogenated nitrile rubber.

[0035] The polyvinyl butyral can function to effectively debundle the bundled single-walled carbon nanotubes, and control the viscosity of the conductive material dispersion at an appropriate level.

[0036] The polyvinyl butyral can be a polymer including a polyvinyl butyral unit, a polyvinyl alcohol unit, and a polyvinyl acetate unit. Specifically, the polyvinyl butyral can include a unit of Formula 2-1, a unit of Formula 2-2, and a unit of Formula 2-3, the polyvinyl butyral unit can correspond to the unit of Formula 2-1, the polyvinyl alcohol unit can correspond to the unit of Formula 2-2, and the polyvinyl acetate unit can correspond to the unit of Formula 2-3.

[0037] [Formula 2-1]

[0038]

[0039] [Formula 2-2]

[0040]

[0041] [Formula 2-3]

[0042]

[0043] The vinyl alcohol units can be included in the polyvinyl butyral at 22 to 50% by weight, specifically 23 to 45% by weight, more specifically 24 to 40% by weight. If the above range is satisfied, the polyvinyl butyral can be easily adsorbed onto the single-walled carbon nanotubes included in the bundled single-walled carbon nanotubes during the preparation of the conductive material dispersion, and it is advantageous to apply a high-pressure homogenizer, and a conductive material dispersion having a lower viscosity than a conductive material dispersion having the same solid content can be prepared. In addition, since the polyvinyl butyral can be easily dissolved in the dispersion medium, the polyvinyl butyral can be uniformly adsorbed on the bundled single-walled carbon nanotubes. Thus, the unbundling of the bundled single-walled carbon nanotubes can be effectively achieved.

[0044] The polyvinyl butyral can be included in the dispersant at 50 to 85% by weight, specifically 55 to 80% by weight, more specifically 65 to 80% by weight. If the above range is satisfied, the unbundling of the bundled single-walled carbon nanotubes can be effectively achieved, and the viscosity of the conductive material dispersion thus prepared can be at a low level.

[0045] The weight average molecular weight of the polyvinyl butyral can be 10,000 to 150,000 g / mol, specifically 15,000 to 30,000 g / mol. If the above range is satisfied, the polyvinyl butyral can be easily dissolved in the dispersion medium, the unbundling of the bundled carbon nanotubes can be easy, the preparation of the conductive material dispersion by the high-pressure homogenizer can be more advantageous, and the viscosity of the conductive material dispersion thus prepared can be at a low level.

[0046] The hydrogenated nitrile rubber serves to reduce the viscosity of the conductive material dispersion, and can be relatively easily dissolved in the dispersion medium to uniformly disperse the carbon nanotubes in the conductive material dispersion.

[0047] The acrylonitrile units can be included in the hydrogenated nitrile rubber at 5 to 50% by weight, specifically 10 to 50% by weight, more specifically 20 to 45% by weight. If the above range is satisfied, the single-walled carbon nanotubes can be advantageously dispersed in the conductive material dispersion, and the viscosity of the conductive material dispersion thus prepared can be at a low level.

[0048] The hydrogenated nitrile rubber can be included in the dispersant at 15 to 50% by weight, specifically 20 to 45% by weight, more specifically 20 to 35% by weight. If the above range is satisfied, the particle diameter of the single-walled carbon nanotubes can be controlled at a low level, and the compatibility with the dispersion medium can be excellent to reduce the viscosity of the conductive material dispersion.

[0049] The weight average molecular weight of the hydrogenated nitrile rubber can be 10,000 g / mol to 700,000 g / mol, specifically 50,000 g / mol to 600,000 g / mol, more specifically 200,000 g / mol to 500,000 g / mol. If the above range is satisfied, the viscosity of the conductive material dispersion can be lowered, the hydrogenated nitrile rubber can be easily dissolved in the dispersion medium, and the bundled single-walled carbon nanotubes can be effectively dispersed so that the single-walled carbon nanotubes are uniformly dispersed in the conductive material dispersion.

[0050] The weight ratio of the polyvinyl butyral and the hydrogenated nitrile rubber can be 5:5 to 9.8:0.2, specifically 5.5:4.5 to 9.5:0.5, more specifically 6:4 to 9:1. If the above range is satisfied, the single-walled carbon nanotubes can be more uniformly dispersed in the conductive material dispersion, and the viscosity of the conductive material dispersion can be at a lower level. Accordingly, the resistance of the manufactured battery can be lowered, and the processability can be improved.

[0051] During the preparation of the conductive material dispersion, a dispersion aid is placed on the surface of the single-walled carbon nanotubes in the bundled single-walled carbon nanotubes to help the polyvinyl butyral and the hydrogenated nitrile rubber adsorb onto the single-walled carbon nanotubes. Accordingly, it is meaningful that the dispersion aid creates a smooth environment for the dispersion of the single-walled carbon nanotubes by the polyvinyl butyral and the hydrogenated nitrile rubber.

[0052] The dispersion aid can include a compound represented by Formula 1.

[0053] [Formula 1]

[0054] A-(R) n

[0055] In Formula 1, A is a structure having 16 to 50 carbons and including four or more aromatic rings and nitrogen, R is a structure including an anionic functional group, and n is an integer of 1 to 5.

[0056] In Formula 1, since A includes four or more aromatic rings, the dispersion aid can be advantageously positioned on the bundled carbon nanotubes through a π-π bond between the dispersion aid and the bundled carbon nanotubes. In addition, since A includes nitrogen, the compatibility between the dispersion aid and the dispersion medium can be excellent, and the hydrogenated nitrile rubber can be easily attached to the bundled carbon nanotubes.

[0057] The aromatic ring can be a benzene ring. Alternatively, the aromatic rings can be close to each other to form a polycyclic ring. Specifically, A can include a group selected from the group consisting of a pyrene group, (crysene) group, a perylene group, and a phthalocyanine group. The phthalocyanine group can or can not include a metal. The metal can be at least any one selected from the group consisting of copper, aluminum, and zinc.

[0058] Meanwhile, the poly(vinyl butyral) and the hydrogenated nitrile rubber can be effectively adsorbed onto the bundle-type carbon nanotube by R, which is a structure including an anionic functional group. Accordingly, in the process of preparing the conductive material dispersion, the bundle-type single-walled carbon nanotube can be effectively un-bundled after pre-mixing, and the conductive material dispersion can be prepared by a high-pressure homogenizer. Accordingly, the single-walled carbon nanotube in the conductive material dispersion can be effectively dispersed when compared with a conductive material dispersion having the same solid content. In addition, these effects can be achieved even if the solid content of the conductive material dispersion is at a high level, and the manufacturing yield of the electrode can be improved by the high solid content of the conductive material dispersion. In addition, the viscosity of the conductive material dispersion can be at a low level, the transport of the conductive material dispersion can be smooth, and the manufacturing processability of the positive electrode can be greatly improved.

[0059] R can be a structure including an anionic functional group, and the anionic functional group can be specifically at least any one selected from the group consisting of -SO3 - , -COO - , and -PO4 - . If n is an integer of 2 or more, the plurality of R can be the same or different.

[0060] n can be an integer of 1 to 5, and specifically can be an integer of 1 to 3.

[0061] Specifically, the compound of formula 1 can be at least any one selected from a compound of formula 1-1 and a compound of formula 1-2.

[0062] [Formula 1-1]

[0063]

[0064] In formula 1-1, R a and R b may each independently be a structure including an anionic functional group. Specifically, the anionic functional group can include at least any one functional group structure selected from the group consisting of -SO3 - , -COO - , and -PO4 - . If the dispersion aid satisfies the structure of formula 1-1, the mutually connected benzene structures are similar to the surface of the single-walled carbon nanotube, they can be well adsorbed to each other, and accordingly, the conductive material dispersion can show a lower viscosity level.

[0065] [Formula 1-2]

[0066]

[0067] In Formula 1-2,

[0068] M can be at least any one selected from the group consisting of copper, aluminum, and zinc.

[0069] R1, R2, R3, and R4 can each independently be an anionic functional group, specifically -SO3 - .

[0070] a, b, c, and d can each independently be any one of an integer of 0 to 4, and at least one of a, b, c, and d can be an integer of 1 to 4.

[0071] If the dispersing aid satisfies the structure of Formula 1-2, the viscosity of the conductive material dispersion can be at a lower level due to the effective adsorption of the phthalocyanine structure and the single-walled carbon nanotube.

[0072] The compound of Formula 1-1 can include at least any one of a compound of Formula 1-1A and a compound of Formula 1-1B.

[0073] [Formula 1-1A]

[0074]

[0075] [Formula 1-1B]

[0076]

[0077] The compound of Formula 1-2 can specifically include at least any one of a compound of Formula 1-2A and a compound of Formula 1-2B.

[0078] [Formula 1-2A]

[0079]

[0080] [Formula 1-2B]

[0081]

[0082] The dispersing aid can be included in 1 parts by weight to 50 parts by weight, specifically 5 parts by weight to 35 parts by weight, more specifically 5 parts by weight to 30 parts by weight, based on 100 parts by weight of the single-walled carbon nanotube. If the above range is satisfied, even if an appropriate amount of the dispersing aid is used, polyvinyl butyral and hydrogenated nitrile rubber can be easily attached to the single-walled carbon nanotube, and the single-walled carbon nanotube can also be effectively dispersed, and the particle diameter of the single-walled carbon nanotube and the viscosity of the conductive material dispersion can be easily controlled.

[0083] The weight ratio of the dispersant and the dispersing aid can be 1:0.03 to 1:0.18, specifically 1:0.045 to 1:0.150. If the above range is satisfied, the particle size of the single-walled carbon nanotube can be at a low level, and the viscosity of the conductive agent dispersion can be very low. At the same time, the dispersant can be well adsorbed on the surface of the single-walled carbon nanotube, and the performance of the high-pressure homogenizer process can be very smooth. Specifically, if the weight ratio is 1:0.045 to 1:0.150, the viscosity of the conductive material dispersion can be at a lower level.

[0084] The dispersing medium can be N-methyl-2-pyrrolidone (NMP).

[0085] The solid content of the conductive material dispersion can be 0.01 to 5% by weight, specifically 0.05 to 4% by weight, and more specifically 0.1 to 3% by weight. Generally, in order to obtain the range of the solid content, there is a problem that the viscosity of the conductive material dispersion is excessively increased. In the present application, although the single-walled carbon nanotube is used, by using the dispersant of the present application, the viscosity of the conductive material dispersion can be controlled at a lower level, and there is no problem in preparing and using the conductive material dispersion having the solid content.

[0086] The viscosity of the conductive material dispersion without phase separation can be 50 Pa-s or less, specifically 0.1 to 40 Pa-s. Since the viscosity range is satisfied, the transport of the conductive material dispersion can be very smooth, and the manufacturing processability of the positive electrode can be greatly improved.

[0087] Hereinafter, preferred embodiments will be presented to help understanding of the present application. However, these embodiments are only for the purpose of illustrating the present application, and various changes and modifications can be made within the scope and technical range of the present description. Of course, such changes and modifications can also be made in the appended claims.

[0088] Examples and Comparative Examples

[0089] The bundle-type carbon nanotube, the dispersant, and the dispersing aid were prepared as follows.

[0090] ① Bundle-type single-walled carbon nanotube, specific surface area 1,160 m 2 / g

[0091] ② Polyvinyl butyral (A-1 to A-3)

[0092] [Table 1]

[0093]

[0094] 3) hydrogenated nitrile rubber having a weight average molecular weight of 30,000 g / mol and including 34 wt% of acrylonitrile units.

[0095] 4) dispersion aids (B-1 to B-5).

[0096] [Table 2]

[0097]

[0098]

[0099] Examples 1 to 8 and Comparative Examples 1 to 8: Preparation of conductive material dispersions

[0100] (1) Pre-mixing

[0101] According to Table 3 below, the bundled type single-walled carbon nanotube, the dispersant, and the dispersion aid were injected into N-methyl-2-pyrrolidone (NMP), and 1 kg of the solution was mixed at 2,000 rpm for 30 minutes using a mechanical mixer.

[0102] (2) Dispersion process

[0103] After that, using a PICOMAX device (high-pressure homogenizer) of Micronox Co., the dispersion process was performed 6 times under the condition of 1,500 bar of pressure. However, in Comparative Examples 4 to 6, phase separation occurred in the solution after pre-mixing, and the phenomenon that the nozzle of the high-pressure homogenizer was clogged with the bundled type single-walled carbon nanotube occurred. Therefore, the process of the high-pressure homogenizer was not feasible.

[0104] [Table 3]

[0105]

[0106]

[0107] The contents of the bundled type carbon nanotube, the polyvinyl butyral, the hydrogenated nitrile rubber, and the dispersion aid were all based on the total weight of the conductive material dispersion, and the sum thereof corresponds to the solid content.

[0108] Examples 9 to 14 and Comparative Examples 9 and 10: Preparation of conductive material dispersions

[0109] (1) Pre-mixing

[0110] The bundle type single-walled carbon nanotubes, dispersant, and dispersion aid were injected into N-methyl-2-pyrrolidone (NMP) according to Table 4 below, and 1 kg of the solution was mixed at 2,000 rpm for 30 minutes using a mechanical mixer.

[0111] (2) Dispersion process

[0112] Thereafter, a dispersion process was performed 6 times at a pressure of 1,500 bar using a PICOMAX apparatus (high-pressure homogenizer) of Micronox Co.

[0113] [Table 4]

[0114]

[0115] The contents of the bundle type carbon nanotubes, polyvinyl butyral, hydrogenated nitrile rubber, and dispersion aid are based on the total weight of the conductive material dispersion, and the sum thereof corresponds to the solid content.

[0116] Test Example 1 : Evaluation of the particle size of single-walled carbon nanotubes

[0117] With respect to the conductive material dispersions of the examples and comparative examples, D 50 was measured three times using a particle size analyzer (Mastersizer 3000 of Micronox Co.), and the average value was obtained, the results of which are shown in Tables 5 and 6.

[0118] When the conductive material dispersions were prepared using the same bundle type single-walled carbon nanotubes, the D 50 value of the single-walled carbon nanotubes in the prepared conductive material dispersions was low, meaning that the bundle type single-walled carbon nanotubes were easily de-bundled and uniformly dispersed in the conductive material dispersion.

[0119] Referring to Table 5, in the case where the conductive material dispersions were prepared using the same amount of bundle type carbon nanotubes, it was found that the D 50 of Examples 1 to 7 was smaller than the D 50 of Comparative Examples 1 to 3, 7, and 8, and thus, the bundle type single-walled carbon nanotubes were effectively dispersed.

[0120] In addition, referring to Table 6, in the case where the conductive material dispersions were prepared using the same amount of bundle type carbon nanotubes, it was found that the D 50 of Examples 9 to 14 was smaller than the D 50 of Comparative Examples 9 and 10, and thus, the bundle type single-walled carbon nanotubes were effectively dispersed.

[0121] Test Example 2: Evaluation of the viscosity of conductive material dispersions

[0122] The viscosity of the conductive material dispersions of the examples and comparative examples was measured using a viscometer TV-22 of TOKI Co. at 25°C and 1 rpm, and the results are shown in Tables 5 and 6.

[0123] When the conductive material dispersions having the same solid content were compared, it was determined that the viscosity of the conductive material dispersions of Examples 1 to 7 was lower than that of the conductive material dispersions of Comparative Examples 1 to 3, 7 and 8. That is, it was found that the conductive material dispersion according to the present application could have a lower viscosity even with a higher solid content.

[0124] In addition, with reference to Table 6, it was determined that the viscosity of the conductive material dispersion was lower in the case of Examples 9 to 12 satisfying the weight ratio of the dispersant and the dispersing aid of 1 : 0.045 to 1 : 0.150, as compared to Examples 13 and 14 deviating from the weight ratio.

[0125] [Table 5]

[0126]

[0127] [Table 6]

[0128]

[0129]

Claims

1. A conductive material dispersion, comprising: Single-walled carbon nanotubes, dispersants, dispersing aids, and dispersion media. The dispersant comprises polyvinyl butyral and hydrogenated nitrile rubber. The solid content of the conductive material dispersion is 0.1% to 3% by weight, wherein the sum of the single-walled carbon nanotubes, the polyvinyl butyral, the hydrogenated nitrile rubber, and the dispersing agent corresponds to the solid content of the conductive material dispersion based on the total weight of the conductive material dispersion. The dispersing agent comprises a compound represented by the following formula 1: [Formula 1] A-(R) n In Formula 1, A is a structure having 16 to 50 carbons and including nitrogen and four or more aromatic rings. R is a structure that includes anionic functional groups, and n is an integer from 1 to 5.

2. The conductive material dispersion according to claim 1, wherein the vinyl alcohol units are included in the polyvinyl butyral at a rate of 22% to 50% by weight.

3. The conductive material dispersion according to claim 1, wherein the single-walled carbon nanotubes are included in the conductive material dispersion at a weight of 0.01% to 5% by weight.

4. The conductive material dispersion of claim 1, wherein the dispersant is included in 10 to 2,000 parts by weight based on 100 parts by weight of the single-walled carbon nanotubes.

5. The conductive material dispersion according to claim 1, wherein the polyvinyl butyral has a weight-average molecular weight of 10,000 g / mol to 150,000 g / mol.

6. The conductive material dispersion according to claim 1, wherein the polyvinyl butyral is included in the dispersion at 50% to 85% by weight.

7. The conductive material dispersion according to claim 1, wherein the hydrogenated nitrile rubber has a weight-average molecular weight of 10,000 g / mol to 700,000 g / mol.

8. The conductive material dispersion according to claim 1, wherein the hydrogenated nitrile rubber is included in the dispersion at 15% to 50% by weight.

9. The conductive material dispersion according to claim 1, wherein the weight ratio of the polyvinyl butyral to the hydrogenated nitrile rubber is 5:5 to 9.8:0.

2.

10. The conductive material dispersion according to claim 1, wherein, In Equation 1, A includes selected free pyrene groups, Any one of the group consisting of α, β-peryl, and phthalocyanine.

11. The conductive material dispersion according to claim 1, wherein R is selected from -SO3 - -COO - and -PO4 - At least one of the groups constituted.

12. The conductive material dispersion according to claim 1, wherein the compound of formula 1 is selected from at least any one of the group consisting of compounds of formulas 1-1 and 1-2: [Equation 1-1] [Equation 1-2] In Equation 1-1, R a and R b Each is independently a structure including anionic functional groups, and In Equations 1-2, M is selected from at least one of the groups consisting of copper, aluminum and zinc, R1, R2, R3 and R4 are each independently anionic functional groups, and a, b, c and d are each independently any integer from 0 to 4.

13. The conductive material dispersion according to claim 12, wherein the compound of formula 1-1 comprises at least any one of the compounds of formula 1-1A and formula 1-1B: [Equation 1-1A] [Equation 1-1B] 14. The conductive material dispersion according to claim 12, wherein the compounds of formula 1-2 comprise at least any one of the compounds of formula 1-2A and the compounds of formula 1-2B: [Equation 1-2A] [Equation 1-2B] 15. The conductive material dispersion of claim 1, wherein the dispersing agent is included in amounts of 1 to 50 parts by weight based on 100 parts by weight of the single-walled carbon nanotubes.

16. The conductive material dispersion according to claim 1, wherein the weight ratio of the dispersant and the dispersing aid is from 1:0.03 to 1:0.

18.

17. The conductive material dispersion according to claim 1, wherein the weight ratio of the dispersant and the dispersing aid is from 1:0.045 to 1:0.150.

Images