KR102382959B1 - Carbon nanotube solution and fabricating method of the same - Google Patents

Abstract

The present invention includes carbon nanotubes, a dispersing agent, and a solvent, and the dispersing agent may include a compound represented by the following Chemical Formula 1 to improve dispersibility and uniformity of the carbon nanotube dispersion.

Description

Carbon nanotube dispersion composition and manufacturing method thereof

The present invention relates to a carbon nanotube dispersion composition and a method for preparing the same. More particularly, it relates to a carbon nanotube dispersion having improved dispersibility and a method for preparing the same.

Fine carbon materials such as carbon black, ketjen black, fullerene, graphene, and carbon nanotubes are widely used in fields such as electronics and energy fields due to their electrical properties and thermal conductivity. In particular, carbon nanotubes, which are a kind of fine carbon fibers, are tubular carbons with a diameter of 1 μm or less, and are expected to be applied and put to practical use in various fields due to their high conductivity, tensile strength, and heat resistance due to their specific structure.

However, despite such usefulness of carbon nanotubes, carbon nanotubes have limitations in their use due to their low solubility and dispersibility. That is, carbon nanotubes do not achieve a stable dispersion state in an aqueous solution due to strong van der Waals attraction with each other, and there is a problem in that aggregation occurs.

Accordingly, a method of dispersing carbon nanotubes in a dispersing agent through mechanical dispersion treatment such as ultrasonic treatment and a method of dispersing and stabilizing carbon nanotubes using various dispersants have been proposed.

However, in the case of the mechanical dispersion treatment, while the ultrasonic wave or the like is irradiated, the dispersibility is excellent, but when the ultrasonic wave or the like is irradiated, there is a problem in that the aggregation of the carbon nanotubes starts again.

Accordingly, in order to expand the use of carbon nanotubes, it is important to use a dispersing agent capable of improving dispersion stability of carbon nanotubes.

For example, Korean Patent Application Laid-Open No. 2016-0107030 attempts to disperse carbon allotropes using ultrasonic waves and shear force application.

Korea Patent Publication No. 2016-0107030 (2015.03.03.)

One object of the present invention is to provide a carbon nanotube dispersion composition having excellent dispersion uniformity and a method for preparing the same.

1. A carbon nanotube dispersion comprising carbon nanotubes, a dispersing agent, and a solvent, wherein the dispersing agent includes a compound represented by the following formula (1):

[Formula 1]

(Wherein, R is hydrogen or a linear or branched alkyl group having 1 to 15 carbon atoms, and X is any one selected from the group consisting of hydrogen, Li, Na and K).

2. The carbon nanotube dispersion according to 1 above, wherein the dispersing agent comprises a compound represented by the following formula (2):

[Formula 2]

(Wherein, R is hydrogen or a linear or branched alkyl group having 1 to 15 carbon atoms, and X is any one selected from the group consisting of hydrogen, Li, Na and K).

3. The carbon nanotube dispersion according to the above 1, wherein the dispersing agent further comprises Tris(2-ethylhexyl) Trimellitate.

4. The carbon nanotube dispersion according to 1 above, wherein the carbon nanotubes include single-walled carbon nanotubes (SWCNTs).

5. In 1 above, the solvent is water, alcohol, acetone, dimethyl sulfoxide, dimethylformamide, benzene, toluene, xylene ( Xylene), chloroform, pyridine, tetrahydrofuran, methyl ethyl ketone, N-methyl-2-piperidone, and methyl isobutyl A carbon nanotube dispersion comprising at least one selected from the group consisting of ketones (methylisobutyl ketone).

6. The carbon nanotube dispersion according to 1 above, comprising 0.01 to 2% by weight of the carbon nanotubes, 1 to 5% by weight of the dispersant, and the remaining amount of the solvent based on the total weight of the carbon nanotube dispersion.

7. Preparing a solution in which carbon nanotubes, a dispersing agent represented by the following Chemical Formula 1, and a dispersing solvent are mixed; and

A method for preparing a carbon nanotube dispersion, comprising dispersing the solution at high pressure:

[Formula 1]

(Wherein, R is hydrogen or a linear or branched alkyl group having 1 to 15 carbon atoms, and X is any one selected from the group consisting of hydrogen, Li, Na and K).

8. The method for producing a carbon nanotube dispersion according to the above 7, wherein the high-pressure dispersion is performed by passing a nozzle by applying a pressure of 200 to 700 bar to the solution at a temperature of 30 to 40°C.

9. The method for producing a carbon nanotube dispersion according to the above 7, wherein the high-pressure dispersing step is performed by repeating mixing using the high-pressure injector for 20 to 60 minutes, 5 to 20 times.

The carbon nanotube dispersion according to the present invention includes a dispersing agent having a specific structure, so that the dispersibility and uniformity of the carbon nanotube dispersion can be further improved.

The present invention provides a carbon nanotube dispersion having improved dispersibility by including a dispersing agent having a specific structure.

Hereinafter, embodiments of the present invention will be described in more detail.

The carbon nanotube dispersion according to an embodiment of the present invention includes carbon nanotubes, a dispersing agent, and a solvent, and the dispersing agent may include a compound represented by the following formula (1).

[Formula 1]

(Wherein, R is hydrogen or a linear or branched alkyl group having 1 to 15 carbon atoms, and X is any one selected from the group consisting of hydrogen, Li, Na and K).

For example, the compound represented by Formula 1 effectively penetrates between carbon nanotubes by a sulfonyl group and an alkyl group substituted with diphenyl oxide, and the benzene ring and sulfonyl group included in the compound represented by Formula 1 are the carbon It can interact with the walls of the nanotubes. Accordingly, the compound represented by Chemical Formula 1 may be positioned between different carbon nanotube particles, thereby effectively inhibiting aggregation of the nanotube particles with each other.

For example, the compound represented by Formula 1 is methyldiphenyloxide disulfonate (methyldiphenyloxide disulfonate), ethyldiphenyloxide disulfonate (ethyldiphenyloxide disulfonate), propyldiphenyloxide disulfonate (propyldiphenyloxide disulfonate), isopropyl Diphenyloxide disulfonate (isopropyldiphenyloxide disulfonate), butyldiphenyloxide disulfonate (butyldiphenyloxide disulfonate), isobutyldiphenyloxide disulfonate (isobutyldiphenyloxide disulfonate), t- butyldiphenyloxide disulfonate (tert-butyldiphenyloxide disulfonate) ), pentyldiphenyloxide disulfonate (pentyldiphenyloxide disulfonate), hexyldiphenyloxide disulfonate (hexyldiphenyloxide disulfonate), heptyldiphenyloxide disulfonate (heptyldiphenyloxide disulfonate), octyldiphenyloxide disulfonate (octyldiphenyloxide disulfonate), It may include at least one selected from the group consisting of nonyldiphenyloxide disulfonate (nonyldiphenyloxide disulfonate) and decyldiphenyloxide disulfonate (decyldiphenyloxide disulfonate).

For example, the dispersant may include a compound represented by Formula 2 below.

[Formula 2]

(Wherein, R is hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms, and X is any one selected from the group consisting of hydrogen, Li, Na and K).

In this case, since the dispersing agent represented by Formula 2 has a hydrophilic sulfonyl group and a hydrophobic alkyl group at an appropriate interval, the benzene ring and the sulfonyl group included in the dispersant represented by Formula 2 interact with the benzene ring and the wall surface of the carbon nanotube The distance between them may be greater. Accordingly, aggregation of carbon nanotubes can be prevented more effectively.

The dispersant of the present application according to exemplary embodiments may further include Tris(2-ethylhexyl) Trimellitate.

For example, tris (2-ethylhexyl) trimellitate (Tris (2-ethylhexyl) trimellitate) can effectively prevent the carbon nanotubes from re-agglomeration by assisting the dispersing agent represented by Formula 1 above.

In exemplary embodiments, the dispersant of the present application contains tris(2-ethylhexyl) trimellitate in an amount of about 10 parts by weight or less based on 100 parts by weight of the dispersant represented by Chemical Formula 1 can do.

For example, when the content of tris(2-ethylhexyl) trimellitate exceeds 10 parts by weight based on 100 parts by weight of the dispersant represented by Formula 1, tris(2-ethylhexyl) trimellitate ) Due to the collision between the trimellitate (Tris (2-ethylhexyl) trimellitate) and the dispersing agent represented by Formula 1, the anti-reagglomeration effect may be reduced.

The carbon nanotube may refer to a material in which a graphite sheet has a cylindrical shape with a nano-size diameter, and has an sp ² bonding structure. In this case, the graphite surface may exhibit conductor or semiconductor characteristics according to a rolling angle and structure.

For example, the carbon nanotube may be a single-walled carbon nanotube (SWCNT), a double-walled carbon nanotube (DWCNT), and multiple It may be classified as a multi-walled carbon nanotube (MWCNT), and the carbon nanotube may be appropriately selected according to the use of the dispersion.

For example, single-walled carbon nanotube (SWCNT) has metallic and semiconducting properties, so it can exhibit various electrical, chemical, physical and optical properties, realizing detailed and integrated devices can be used for the purpose of

The carbon nanotubes according to exemplary embodiments include single-walled carbon nanotube (SWCNT), double-walled carbon nanotube (DWCNT, double-walled carbon nanotube), and multi-walled carbon nanotube (MWCNT, multi-walled carbon nanotube). -walled carbon nanotube) may include at least one selected from the group consisting of, and preferably may include a single-walled carbon nanotube (SWCNT, single-walled carbon nanotube). When the carbon nanotube includes a single-walled carbon nanotube (SWCNT), electrical properties suitable for the use of the dispersion may be more easily realized.

For example, the carbon nanotubes may be manufactured by a conventional method such as an arc discharge method, a laser evaporation method, or a chemical vapor deposition method, or commercially available carbon nanotubes may be obtained and used.

In some exemplary embodiments, the solvent is water, alcohol, acetone, dimethyl sulfoxide, dimethylformamide, benzene, toluene, xyl Xylene, chloroform, pyridine, tetrahydrofuran, methyl ethyl ketone, N-methyl-2-piperidone, and methyl It may include at least one selected from the group consisting of isobutyl ketone (methylisobutyl ketone). Preferably, the solvent may include water or alcohol.

In some exemplary embodiments, the carbon nanotube dispersion composition may include about 0.01 to 2% by weight of the carbon nanotubes, about 1 to 5% by weight of the dispersant, and the remaining amount of the solvent based on the total weight of the dispersion. . For example, when the content of the carbon nanotubes, the dispersant, and the solvent included in the dispersion satisfies the above ranges, the dispersion may have excellent stability and uniformity.

Hereinafter, a method for preparing a carbon nanotube dispersion according to exemplary embodiments will be described.

The present invention prepares a solution in which the carbon nanotubes, the dispersing agent represented by Formula 1, and the dispersing solvent are mixed. The solution is dispersed at high pressure to prepare a carbon nanotube dispersion.

The carbon nanotubes, the dispersant, and the solvent may be used in the kind and content contained in the above-described tano nanotube dispersion.

In some exemplary embodiments, the high-pressure dispersion may be performed using a high-pressure disperser.

For example, the high-pressure disperser may include a high-pressure homogenizer. For example, the high-pressure dispersion may be performed at 200 to 700 bar conditions using a high-pressure homogenizer or the like. In this case, as a strong pressure is applied to the solution, the size of the particles included in the solution is reduced, so that the particles in the solution can be evenly dispersed.

For example, the solution may be passed through a nozzle by applying a pressure of about 200 to 700 bar at a temperature of about 30 to 40° C. using the high-pressure disperser. When the temperature and pressure ranges are satisfied, a sufficient impact force acts on the carbon nanotubes, so that the dispersibility and dispersion stability of the carbon nanotube dispersion may be further improved.

For example, the high-pressure dispersion may be repeated about 5 to 20 times for about 20 to 60 minutes using the high-pressure disperser. In the high-pressure dispersion condition range, a sufficient impact force acts on the carbon nanotubes, so that the dispersibility and dispersion stability of the carbon nanotube dispersion prepared may be further improved.

The carbon nanotube dispersion is, for example, an antistatic material, an electrostatic dissipation material, a conductive material, an electromagnetic wave shielding material, an electromagnetic wave absorber, a radio frequency (RF) absorber, a material for a solar cell, an electrode material for a fuel sensitive cell, an electric device material, a semiconductor device Materials, optoelectronic device materials, notebook parts materials, computer parts materials, mobile phone parts materials, PDA parts materials, PSP parts materials, game machine parts materials, housing materials, transparent electrode materials, opaque electrode materials, field emission display materials, BLU(back) light unit) material, liquid crystal display device material, plasma display panel material, light emitting diode material, touch panel material, electric sign board material, billboard material, display material, heating element, heat sink, plating material, catalyst, co-catalyst, oxidizing agent, reducing agent, automobile Part materials, ship parts materials, aircraft parts materials, masking tape materials, adhesive materials, tray materials, clean room materials, transportation equipment parts materials, flame retardant materials, antibacterial materials, metal composite materials, non-ferrous metal composite materials, medical device materials , building material, flooring material, wallpaper material, light source component material, lamp material, optical device component material, textile manufacturing material, clothing manufacturing material, electrical appliance material, electronic product manufacturing material, positive electrode active material for secondary batteries, negative electrode active material for secondary batteries, It can be used as a secondary battery material, a fuel cell material, a solar cell material, a memory device, and a capacitor (P-ED<C) material.

Hereinafter, preferred embodiments are presented to help the understanding of the present invention, but these examples are merely illustrative of the present invention and do not limit the appended claims, and are within the scope and spirit of the present invention. It is obvious to those skilled in the art that various changes and modifications are possible, and it is natural that such variations and modifications fall within the scope of the appended claims.

Example 1

0.1 parts by weight of single-walled carbon nanotubes (zeonano # SG101), 3 parts by weight of butyldiphenyloxide disulfonate as a dispersing agent, and 100 parts by weight of water were mixed to prepare a mixed solution of 100 ml in total.

A carbon nanotube dispersion was prepared by applying a pressure of 500 bar at 35° C. to the mixed solution using a high-pressure disperser (NLM 100, Ilshin). This process was repeated 10 times for 40 minutes.

Example

A carbon nanotube dispersion was prepared in the same manner as in Example 1, except that different types and content ranges of carbon nanotubes, dispersants, and solvents were added as shown in the table below.

Comparative Example 1

A reduced graphene oxide dispersion was prepared in the same manner as in Example 1, except that thiourea was added in the same amount instead of ethylcellulose.

division carbon nanotubes dispersant solvent type content type content type content Example 1 A-1 0.1 B-1 One C-1 remaining amount Example 2 A-1 0.1 B-1 2 C-1 remaining amount Example 3 A-1 0.1 B-1 3 C-1 remaining amount Example 4 A-1 0.1 B-1 4 C-1 remaining amount Example 5 A-1 0.1 B-1 5 C-1 remaining amount Example 6 A-1 0.1 B-1 2.8 C-1 remaining amount B-2 0.2 Example 7 A-1 0.1 B-1 2.7 C-1 remaining amount B-2 0.3 Comparative Example 1 A-1 0.1 B-2 3 C-1 remaining amount Comparative Example 2 A-1 0.1 - - C-1 remaining amount A-1: Single-walled carbon nanotubes
B-1: Butyldiphenyloxide disulfonate
B-2: Tris (2-ethylhexyl) trimellitate
C-1: water

Experimental Example 1: Absorbance evaluation

For the carbonate nanotube dispersions prepared according to the Examples and Comparative Examples, the absorbance for 500 nm wavelength light was measured using a UV-Visible spectrometer (SCINCO's MEGA-800 model: 190 nm to 1100 nm analysis possible).

The measurement results are shown in Table 2 below.

Experimental Example 2: Precipitation evaluation

The carbon nanotube dispersions prepared according to Examples and Comparative Examples were centrifuged at 100 g speed for 40 minutes using a centrifuge (LABOGENE 1248 model manufactured by LABOGENE). The concentration of the carbon nanotube dispersion before and after centrifugation was measured based on the absorbance of 500 nm wavelength light using a UV-Visible spectrometer (SCINCO's MEGA-800 model: 190 nm ~ 1100 nm analysis possible). The concentration ratio of the carbon nanotube dispersion after centrifugation to the concentration of the carbon nanotube dispersion before centrifugation was calculated as the precipitation degree. The results are shown in Table 2 below.

Experimental Example 3: Measurement of surface resistance

A carbon nanotube coating layer having an area of 2 inches by 2 inches and a thickness of 10 μm was formed on the surface of the substrate using the carbon nanotube dispersion having a mass percent concentration of 0.1 wt% prepared according to the Examples and Comparative Examples. did. The surface resistance of the formed carbon nanotube coating layer was measured using a model name ST-4 (SIMCO). The surface resistance of the carbon nanotube coating layer was randomly measured at five places using the above equipment, and the average value thereof was obtained and is shown in Table 2 below.

division Absorbance (L/g cm) Sedimentation Assessment (%) Surface resistance (Ω/□) Example 1 0.046 90 10 ^5.9 Example 2 0.048 92 10 ^6.2 Example 3 0.049 95 10 ^6.4 Example 4 0.049 95 10 ^6.7 Example 5 0.051 96 10 ^7.1 Example 6 0.050 94 10 ^6.5 Example 7 0.048 95 10 ^6.5 Comparative Example 1 0.020 68 10 ^9.7 Comparative Example 2 0.023 70 10 ^9.2

Referring to the above table, Examples including butyldiphenyloxide disulfonate showed excellent precipitation evaluation results and surface resistance. In particular, when a mixture of butyldiphenyloxide disulfonate and tris(2-ethylhexyl) trimellitate was included, the surface resistance was reduced, and improved electrical properties were exhibited.

Claims (9)

preparing a solution in which carbon nanotubes, a dispersant, and a solvent are mixed; and
dispersing the solution at high pressure;
The dispersant includes a compound represented by the following formula (1) and tris (2-ethylhexyl) trimellitate (Tris (2-ethylhexyl) trimellitate),
The content of the dispersant is 1 to 5% by weight based on the total weight of the dispersion, the method for producing a carbon nanotube dispersion:
[Formula 1]

(Wherein, R is hydrogen or a linear or branched alkyl group having 1 to 15 carbon atoms, and X is any one selected from the group consisting of hydrogen, Li, Na and K).
The method according to claim 1, wherein the dispersant comprises a compound represented by the following formula (2):
[Formula 2]

(Wherein, R is hydrogen or a linear or branched alkyl group having 1 to 15 carbon atoms, and X is any one selected from the group consisting of hydrogen, Li, Na and K).
delete The method according to claim 1, wherein the carbon nanotubes include SWCNTs.
The method according to claim 1, wherein the solvent is water, alcohol, acetone, dimethyl sulfoxide, dimethylformamide, benzene, toluene, xylene. , chloroform (Chloroform), pyridine (Pyridine), tetrahydrofuran (Tetrahydrofuran), methyl ethyl ketone (methyl ethyl ketone), N-methyl-2-piperidone (N-methyl-2-pyrrolidone) and methyl isobutyl ketone ( A method for producing a carbon nanotube dispersion comprising at least one selected from the group consisting of methylisobutyl ketone).
The method according to claim 1, wherein the carbon nanotube dispersion contains 0.01 to 2% by weight of the carbon nanotubes and the remaining amount of the solvent based on the total weight of the dispersion.
delete The method according to claim 1, wherein the high-pressure dispersion is performed by passing a nozzle through a nozzle by applying a pressure of 200 to 700 bar to the solution at a temperature of 30 to 40°C.
The method according to claim 1, wherein the high-pressure dispersing step is performed by repeating mixing using the high-pressure injector for 20 to 60 minutes, 5 to 20 times.