KR101295351B1 - Dispersant Composition for Carbon Nanotubes, Carbon Nanotube Composite Comprising the Dispersant Composition and Polymer Composite Material Produced Using the Carbon Nanotube Composite - Google Patents

Abstract

The present invention relates to a dispersant composition for carbon nanotubes comprising a polysiloxane-poly (ethylene / propylene glycol) graft copolymer as a main dispersant and a polyethylene glycol-based compound as an auxiliary dispersant. In the main dispersant, polysiloxane constitutes the main chain of the copolymer and poly (ethylene / propylene glycol) constitutes the side chain of the copolymer. When melt kneading the carbon nanotubes treated with the dispersant composition of the present invention with various polymers, the carbon nanotubes are uniformly dispersed in the polymer to prepare a masterbatch or compound polymer composite in which conductivity and overall physical and mechanical properties are greatly modified. have.

Description

Dispersant composition for carbon nanotubes, carbon nanotube composites including the dispersant composition and polymer composites prepared using the carbon nanotubes composites.Dispersant Composition for Carbon Nanotubes, Carbon Nanotube Composite Comprising the Dispersant Composition and Polymer Composite Material Produced Using the Carbon Nanotube Composite}

The present invention relates to a carbon nanotube / polymer composite such as a dispersant composition capable of effectively dispersing carbon nanotubes, a carbon nanotube composite including the dispersant composition, and a master batch manufactured using the carbon nanotube composite.

Carbon nanotubes have been at the center of so-called nanotechnology since the discovery of Ijima in Japan in 1991. Carbon nanotubes are molecules of 1 to 20 nm in diameter, formed by combining carbon atoms in a hexagonal shape, and their planes are rolled in a long shape. They are more than 100 times stronger than steel, and are more thermally conductive than diamond. Very stable Carbon nanotubes exhibit various electrical characteristics ranging from insulators to semiconductors to metallics, depending on the diameter and arrangement of carbon molecules constituting the long side, and due to their hollow structure, molecular transistors, energy storage, 2 It has attracted much attention as various electronic devices of nano size, such as a battery electrode, a nanowire, an electron emission source, and a flat panel display device.

However, in order to apply carbon nanotubes to the modification of polymer and metal materials in various electronic devices such as conductive film formation, electromagnetic wave shielding agent, negative electrode active material, nano lubricant, planar heating element, strength reinforcing agent, and light emitting device, It must be effectively dispersed in the polymer matrix. Carbon nanotubes are physically and chemically agglomerated, and physical agglomeration is a nanotube intertwined and wound with each other as individual particles at a micrometer level, and chemical agglomeration is a single-walled carbon nanotube (SWCNT) at nm level. As in the case of this case, it is agglomerated by surface forces (~ 950 meV / nm) such as the intermolecular van der Waals force. Since the coagulation phenomenon of carbon nanotubes prevents the formation of a three-dimensional network structure that can improve mechanical strength and conduction properties, carbon nanotube dispersion problem is not a problem that can be easily solved unlike other materials. Carbon nanotubes have been tried in particular in conductive polymer applications, but nanotubes are not completely dispersed in the polymer matrix, and thus, the advantages of nanotubes as fillers are not properly exhibited.

Carbon nanotubes are difficult to achieve molecular-level dispersion by conventional methods such as simply applying physical mixing power or ultrasonic waves. Therefore, carbon nanotubes have high surface compatibility with carbon nanotubes, which improves compatibility with the matrix or uses various surfactants. Have been reported to increase the For example, a method of improving matrix compatibility of carbon nanotubes by attaching one or more functional groups among cyan, amine, hydroxy, carboxyl, halide, nitrate, thiocyanate, thiosulfate and vinyl groups to carbon nanotubes. Although these modifications have been proposed, some of the dispersibility may be improved, but they may be expensive and decisively reduce the intrinsic properties of the carbon nanotubes.

On the other hand, a method of increasing the solubility or dispersity has been proposed by wrapping the carbon nanotubes with a polymer or a dispersant that can physically interact with the carbon nanotubes instead of direct modification. Japanese Patent Application Laid-Open No. 2005-219986 describes a carbon nanotube dispersion using an aromatic polyamide as a dispersant, and Korean Patent No. 10-0851983 describes a carbon nanotube dispersion using an ethylene oxide-propylene oxide block copolymer. It is claimed that the dispersion stability of nanotubes can be used for both aqueous and organic dispersions and thus can be used for manufacturing transparent electrodes. In addition, Korean Patent Publication No. 10-2007-0116856 describes a method of using a variety of diblock, triblock copolymer as a dispersant, and Korean Patent No. 10-0804072 discloses an amphiphilic block Provided is a method for dispersing single-walled carbon nanotubes, wherein the single-walled carbon nanotubes are dispersed using a micelle of a copolymer.

Similar to using the block copolymer as a dispersant, Korean Patent No. 10-0735996 and Korean Patent No. 10-0735996 have high compatibility with carbon nanotubes to form a head part and relatively relatively to the head part. A method of dispersing carbon nanotubes using a kind of surfactant which forms a tail part with an acrylic polymer having low hydrophobic properties as a dispersant has been proposed.

However, the above methods for improving carbon nanotube dispersion by modifying carbon nanotubes themselves and using linear block copolymers as dispersants are limited in dispersing carbon nanotubes because the disassembly of carbon nanotube bundles is not complete. There was. In addition, carbon nanotube dispersions have generally been prepared by dispersing carbon nanotubes in an aqueous solvent. However, dispersibility is remarkably poor in an organic solvent or a polymer matrix, and an excess dispersant may be used to increase dispersion in an organic solvent or a polymer matrix. Excess dispersant may act as a foreign material that interferes with the properties of the carbon nanotubes in terms of the final device or final polymer blend. Therefore, it is necessary to disperse a large amount of carbon nanotubes efficiently (that is, at a high concentration) in an organic solvent or a polymer matrix with a small amount of a dispersant.

The inventors of the present invention have solved the above-mentioned problems of the prior art, and have concentrated on research to develop a new kind of dispersant composition for carbon nanotubes having excellent dispersing effect and stability compared to the conventional dispersing agent and dispersant composition for carbon nanotubes. The present invention has been completed by discovering that a mixture of a poly (ethylene / propylene glycol) graft copolymer and a polyethylene glycol compound has an excellent effect on dispersing carbon nanotubes in a polymer matrix.

Accordingly, an object of the present invention is to provide a dispersant composition which can effectively disperse carbon nanotubes using a polysiloxane-poly (ethylene / propylene glycol) graft copolymer as a main dispersant and a polyethylene glycol compound as an auxiliary dispersant. .

Still another object of the present invention is to provide a carbon nanotube composite including the dispersant composition for carbon nanotubes.

Another object of the present invention to provide a polymer composite prepared using the carbon nanotube composite.

In order to achieve the above object, the present invention provides a carbon nano comprising a polysiloxane-poly (ethylene / propylene glycol) graft copolymer represented by the following Chemical Formula 1 as a main dispersant and a polyethylene glycol compound represented by the following Chemical Formula 2 as an auxiliary dispersant: A dispersant composition for a tube is provided:

Wherein R is a hydrogen atom or a methyl group, m is an integer from 0 to 50, n is an integer from 0 to 50, m + n is 0 to 50, x is an integer from 10 to 50, y is An integer from 10 to 35, and x + y is from 20 to 85.)

(Wherein R is a hydrogen atom or a methyl group and n is an integer from 11 to 110).

In one embodiment of the present invention, the polysiloxane, poly (ethylene / propylene glycol) copolymer (Formula 1) and polyethylene glycol-based compound (Formula 2) is characterized in that it is included in a weight ratio of 1: 1 to 5: 1 do.

In one embodiment of the present invention, the graft copolymer is characterized in that the number average molecular weight is 5,000 to 50,000 and the graft rate is 50 to 90%.

In one embodiment of the present invention, the graft copolymer is characterized in that the liquid phase is a viscosity of 200 to 2,500 cps at 25 ℃.

In one embodiment of the present invention, the number average molecular weight of the polyethylene glycol compound is characterized in that 500 to 5,000.

The present invention also provides a carbon nanotube composite comprising the dispersant composition.

In one embodiment, the mixing weight ratio of the dispersant composition and carbon nanotubes is characterized in that 0.1-30: 70-99.9.

The present invention also provides a polymer composite prepared using the carbon nanotube composite.

In one embodiment, the polymer is polyolefin, polyacrylonitrile butadiene styrene (ABS), polystyrene, polymethyl methacrylate (PMMA), nylon, polycarbonate, polyoxymethylene, polyethersulfone, polyphenylene oxide ( PPO), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyetherimide (PEI) and one or more selected from the group consisting of modified substances thereof It is characterized by.

The present invention also provides a coating liquid comprising the carbon nanotube composite.

The dispersant composition for carbon nanotubes of the present invention can highly disperse carbon nanotubes even by using a small amount and can produce various types of carbon nanotube composites such as powders. In addition, when the carbon nanotube composite of the present invention is melt-kneaded with various polymers in a conventional manner, a carbon nanotube / polymer composite having carbon nanotubes uniformly dispersed in a polymer matrix can be obtained. In addition, the carbon nanotube composite according to the present invention can be stably dispersed in the polymer matrix as a dispersion medium to produce a conductive plastic product through injection and extrusion, and to produce a coating solution in which carbon nanotubes are stably dispersed in a solvent as a dispersion medium. .

Hereinafter, the present invention will be described in detail with reference to preferred embodiments.

Graft copolymers, like linear block copolymers, are known to exhibit surfactant properties and are often used as compatibilizers to increase the mixing of two polymers of different solubility, especially in polymer blends. In the present invention, using the properties of these graft copolymers, it was conceived that a copolymer composed of a polysiloxane and a poly (ethylene / propylene glycol) copolymer is suitable for dispersing carbon nanotubes.

Specifically, the dispersant composition for carbon nanotubes of the present invention includes a graft copolymer of polysiloxane and a poly (ethylene / propylene glycol) copolymer as a main dispersant and a polyethylene glycol compound as an auxiliary dispersant.

The graft copolymer has a main chain made of polysiloxane and a side chain made of a poly (ethylene / propylene glycol) copolymer, and preferably has a graft ratio of 50 to 90%. Here, 'degree of grafting' means the ratio of the molecular weight of the side chain component to the total molecular weight of the graft copolymer.

The polysiloxane is a hydrophobic polymer easily adsorbed to carbon nanotubes, and the poly (ethylene / propylene glycol) copolymer is relatively high in hydrophilicity and is an effective polymer for dispersing carbon nanotubes. The amphipathic properties of such graft copolymers can be effectively adsorbed onto the carbon nanotubes and dispersed.

The graft copolymer is poly [dimethylsiloxane-co-methyl (3-hydroxypropyl) siloxane] -graft-poly (ethylene / propylene glycol) represented by Formula 1 below:

(1)

(One)

Wherein R is a hydrogen atom or a methyl group, m is an integer from 0 to 50, n is an integer from 0 to 50, m + n is 0 to 50, x is an integer from 10 to 50, y is 10 An integer from to 35, and x + y is from 20 to 85.

The number average molecular weight of the graft copolymer of Formula 1 is 5,000 to 100,000, preferably 5,000 to 50,000. If the molecular weight is 100,000 or more, the viscosity is too high, the carbon nanotube dispersion effect of the final composition is poor, which is not preferable. The molecular weight of the polyethylene glycol compound is preferably about 60 to 80% of the total molecular weight of the graft copolymer. The graft copolymer of Chemical Formula 1 is preferably in a liquid phase having a viscosity of 200 to 2,500 cps at 25 ° C. Wetting characteristics important for dispersion treatment of carbon nanotubes within this viscosity range are good. If it is higher than 2,500 cps, it becomes almost impossible to disintegrate-disperse the aggregated nanotubes.

The graft copolymer of Chemical Formula 1 may be prepared conventionally by well-known synthetic methods such as hydrosilylation. For example, dimethylpolysiloxanes containing hydrosilyl groups (Si-H) and poly (ethylene oxide), poly (propylene oxide) or poly (ethylene oxide-co- Propylene oxide) may be reacted under a metal catalyst such as platinum to prepare a graft copolymer in which an oxide polymer is added as a side chain to a polydimethylsiloxane main chain. Depending on the experimental conditions, graft copolymers having various molecular weights and graft ratios can be easily synthesized. Indeed, in the examples of the present invention, commercially available ones were used.

The polyethylene glycol-based compound as the auxiliary dispersant is polyethylene glycol, polyethylene glycol monomethyl ether or polyethylene glycol dimethyl ether represented by the following general formula (2):

(2)

(2)

Wherein R is a hydrogen atom or a methyl group and n is an integer from 11 to 110.

The molecular weight of the co-dispersant is preferably 500 to 5,000, more preferably 1,000 to 2,000. These auxiliary dispersants exhibit a strong carbon nanotube dispersion effect together with the main dispersant, and are known to exhibit surfactant properties to some extent and to exhibit compatibilizer properties to a considerable extent with polymers.

The main dispersant and the auxiliary dispersant may be mixed in various ranges according to the type of the polymer to be kneaded (blending) with the carbon nanotubes. In the present invention, the main dispersant and the auxiliary dispersant are mixed in a weight ratio of 1: 1 to 5: 1, preferably 2: 1 to 3: 1.

In addition, the carbon nanotube composite of the present invention is prepared by mixing the carbon nanotube dispersant composition and carbon nanotubes.

The mixing ratio of the dispersant composition and the carbon nanotubes is not particularly limited, but is preferably 0.1-30: 70-99.9 weight ratio. Within this range, the dispersing effect of the carbon nanotubes by the dispersant composition is greatly exhibited.

The type and detailed characteristics of the carbon nanotubes used in the carbon nanotube composite of the present invention are not particularly limited, and both single-walled and multi-walled carbon nanotubes are possible.

Carbon nanotube composite of the present invention can be prepared as follows. First, after adding an appropriate amount of the dispersant composition of the present invention to the carbon nanotubes, the mixture is mixed well with each other at high speed for 30 minutes to 1 hour. The mixer used here does not need to be a special device, and general mechanical mixers, homogenizers, etc. may be used, but it is preferable to be able to apply non-directional shearing force at high speed if possible. The obtained composite may be obtained in various forms such as powder or slurry depending on the type and molecular weight of the auxiliary dispersant and the mixing ratio of the dispersant composition and the carbon nanotubes.

The polymer composite of the present invention is prepared using the polymer as the carbon nanotube composite and the dispersion medium. The mixing method is not particularly limited, and melt blending in a conventional manner may yield a polymer nanocomposite in the form of a masterbatch or compound in which carbon nanotubes are uniformly dispersed in a polymer matrix.

The coating agent of the present invention can be prepared by dispersing the carbon nanotube composite in a solvent as a dispersion medium.

Conventionally, in order to manufacture a carbon nanotube / polymer composite material, it was difficult to expect sufficient dispersion effect of carbon nanotubes because it was kneaded and kneaded together with a dispersant composition and a polymer at a time without a separate carbon nanotube dispersion process. In addition, when using a conventional carbon nanotube dispersant composition containing a polyethylene glycol-based compound, molecular migration of the polyethylene glycol-based compound occurs in the polymer matrix and elutes to the surface of the polymer composite to act as a contaminant on the surface of the product. have. In contrast, in the present invention, carbon nanotubes are melt-kneaded with the polymer after sufficiently dispersing the carbon nanotubes in the state adsorbed on the surface of the carbon nanotubes using the dispersant composition of the present invention before melt-kneading the carbon nanotubes with the polymer. Molecular migration and surface elution of polyethylene glycol compounds do not occur even after long-term storage at. The graft copolymer, which is the main dispersant, forms a kind of micelle in the polymer matrix and the polyethylene glycol compound is stably located in the micelle, or the polymer, the main dispersant and the auxiliary dispersant are dispersed and bonded at the molecular level to prevent molecular migration. It is judged.

The polymer composite material of the present invention can express excellent electrical properties even with a small amount of carbon nanotubes when the carbon nanotube-dispersant composite is added to the polymer and melt kneaded. In more detail, when 0.5 to 30 wt% of the dispersant-carbon nanotube composite is mixed with 70 to 99.5 wt% of the polymer and melt-kneaded, electric conductivity of 10 ^-2 to 10 ¹² is obtained according to the carbon nanotube content and the type of the polymer. Can be. The kneading apparatus used at this time is sufficient as a conventional extruder, such as a twin screw extruder, and is not specifically limited. In the polymer composite of the present invention, the carbon nanotubes contained in a predetermined amount in the matrix are satisfactorily dispersed, thereby lowering the surface resistance. In general, the surface resistance of the polymer containing no carbon nanotubes is about 10 ¹⁴ Ω / sq. When carbon nanotubes are added to the polymer, the surface resistance decreases due to the conductive properties of the carbon nanotubes. However, if the dispersion is not sufficient, the surface resistance does not decrease as expected even when a large amount is added. In the present invention, the surface resistance of the polymer composite is 10 ¹⁰ Ω / sq. It can be lowered below.

The type of polymer used in the polymer composite of the present invention is not particularly limited, and general-purpose polymers such as polyacrylonitrile butadiene styrene (ABS), polystyrene, polymethyl methacrylate (PMMA) from polyolefins such as polyethylene and polypropylene, Engineering plastics such as nylon, polycarbonate, polyoxymethylene, polyethersulfone, polyphenylene oxide (PPO), polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or polyphenylene sulfide (PPS), poly Excellent results are also found when applied to superengineering plastics such as etherimide (PEI).

Hereinafter, the present invention will be described in detail through specific examples. However, the scope of the present invention is not limited by the following examples.

Example

Example  One

For carbon nanotubes Dispersant  Composition and Carbon Nanotube Composite Preparation

100 g of poly [dimethylsiloxane-co-methyl (3-hydroxypropyl) siloxane] -graft-poly (ethylene / propylene glycol) (number average molecular weight 20,000; graft rate 80%) as a main dispersant and polyethylene glycol mono as a dispersant 30 g of methyl ether (number average molecular weight 2,000) was put into a stirrer and stirred for 30 minutes. At this time, the temperature of the stirrer was maintained at 45 ° C. 140 g of the prepared mixture and 500 g of carbon nanotubes (NANOCYL, NC-7000 (average diameter: 9.5 nm, average length: 1.5 μm purity: 90%)) were added to another mixer, and stirred at high speed for 1 hour to form a powder. A carbon nanotube composite was obtained.

Carbon Nanotube / Polymer Composite Manufacturing

40 kg of modified polyphenylene oxide (m-PPO) pulverized into particle sizes of 10 to 100 mesh was added to a super mixer, and 225 g of the carbon nanotube composite prepared above was added thereto, followed by sufficient mixing at high speed. The compound chip obtained by injecting into a main feeder and injecting 5 kg of glass fibers into a side feeder was injected.

Example  2

A carbon nanotube / polymer composite was prepared in the same manner as in Example 1 except that the amount of the auxiliary dispersant was changed to 50 g to prepare a dispersant composition for carbon nanotubes.

Example  3

A carbon nanotube / polymer composite was prepared in the same manner as in Example 1 except that the amount of the auxiliary dispersant was changed to 70 g to prepare a dispersant composition for carbon nanotubes.

Example  4

A carbon nanotube / polymer composite was prepared in the same manner as in Example 1 except that the amount of the main dispersant and the auxiliary dispersant was changed to 50 g and 25 g, respectively, to prepare a dispersant composition for carbon nanotubes.

Example  5

The carbon nanotube / polymer composite material was prepared in the same manner as in Example 1, except that the amount of the main dispersant and the auxiliary dispersant was changed to 200 g and 100 g, respectively, to prepare a dispersant composition for carbon nanotubes and 1,000 g of carbon nanotubes were used. Was prepared.

Example  6

A carbon nanotube / polymer composite was prepared in the same manner as in Example 1, except that the dispersion composition for carbon nanotubes was prepared without using an auxiliary dispersant.

Example  7

A carbon nanotube / polymer composite was prepared in the same manner as in Example 2 except that polyethersulfone was used instead of m-PPO.

Example  8

A carbon nanotube / polymer composite was prepared in the same manner as in Example 5 except that polycarbonate was used instead of m-PPO.

Example  9

A carbon nanotube / polymer composite was prepared in the same manner as in Example 1, except that 50 g of polyethylene glycol (number average molecular weight 2,000) was used as an auxiliary dispersant to prepare a dispersant composition for carbon nanotubes.

Example  10

A carbon nanotube / polymer composite was prepared in the same manner as in Example 1 except that 50 g of polyethylene glycol dimethyl ether (number average molecular weight 2,000) was used as an auxiliary dispersant to prepare a dispersant composition for carbon nanotubes.

Comparative example  One

A carbon nanotube / polymer composite was prepared in the same manner as in Example 1 except that the amount of the auxiliary dispersant was changed to 100 g to prepare a dispersant composition for carbon nanotubes.

Comparative example  2

A carbon nanotube / polymer composite was prepared in the same manner as in Example 1, except that the dispersant composition for carbon nanotubes was prepared by changing the amount of the auxiliary dispersant to 100 g without using the main dispersant.

Comparative example  3

A carbon nanotube / polymer composite was prepared in the same manner as in Example 1, except that 50 g of polyethylene glycol monomethyl ether having a number average molecular weight of 750 was used as an auxiliary dispersant to prepare a dispersant composition for carbon nanotubes.

Comparative example  4

A carbon nanotube / polymer composite was prepared in the same manner as in Example 1, except that 50 g of polyethylene glycol monomethyl ether having a number average molecular weight of 5,000 was used as an auxiliary dispersant to prepare a dispersant composition for carbon nanotubes.

Test Example  1: Surface resistance measurement

30 minutes after the carbon nanotube / polymer composite specimens were injected in Examples 1-10 and Comparative Examples 1-4, the surface resistance was measured using a surface resistance measuring instrument (ST-3, manufactured by SIMCO), and the results Is shown in Table 1.

Test Example  2: Observe surface condition

In Example 1-10 and Comparative Example 1-4, the carbon nanotube / polymer composite specimen was left at room temperature for 2 weeks, and then the surface state was observed. It was judged that there was elution when greasy grease was observed on the surface when visual observation was observed, and when the distinction was not sufficient, the surface was washed with a solvent such as methyl ethyl ketone (MEK) and the cleaning solution was analyzed by HPLC. Confirmed. Table 1 shows only visual results.

Surface Resistance and Surface Condition of Carbon Nanotube / Polymer Composites Main Dispersant (g) Auxiliary dispersant ^{1 )} (g) NC-7000 (g) Polymer (kg) Surface resistance (Ω / sq.) Surface condition Example 1 100 30 500 40 10 ⁸ No dissolution Example 2 100 50 500 40 10 ⁷ No dissolution Example 3 100 70 500 40 10 ⁷ No dissolution Example 4 50 25 500 40 10 ¹⁰ No dissolution Example 5 200 100 1,000 40 10 ² No dissolution Example 6 100 0 500 40 10 ¹⁰ No dissolution Example 7 100 50 500 40 ⁶⁾ 10 ⁵ No dissolution Example 8 200 100 1,000 40 ⁷⁾ 10 ³ No dissolution Example 9 100 50 ⁴⁾ 500 40 10 ⁷ No dissolution Example 10 100 50 ⁵⁾ 500 40 10 ⁷ No dissolution Comparative Example 1 100 100 500 40 10 ⁷ Dissolution Comparative Example 2 0 100 500 40 10 ¹² Dissolution Comparative Example 3 100 50 ²⁾ 500 40 10 ⁷ Dissolution Comparative Example 4 100 50 ³⁾ 500 40 10 ¹⁰

¹⁾ Polyethylene glycol monomethyl ether (number average molecular weight 2,000)

²⁾ Polyethylene Glycol Monomethyl Ether (Number Average Molecular Weight 750)

³⁾ Polyethylene Glycol Monomethyl Ether (Number Average Molecular Weight 5,000)

⁴⁾ Polyethylene glycol (number average molecular weight 2,000)

⁵⁾ Polyethylene glycol dimethyl ether (number average molecular weight 2,000)

⁶⁾ Polyethersulfone (weight average molecular weight 100,000, SOLVAY, PES 3600P)

⁷⁾ Polycarbonate (weight average molecular weight 75,000)

As can be seen from the results of Table 1, the mixing ratio of the main dispersant and the auxiliary dispersant was found to be around 2: 1 (Examples 1 to 3), and the surface resistance could be adjusted according to the dosage of the dispersant mixture. It can know (Examples 4-5). In addition, it was found that the main dispersant exhibits a dispersion effect of carbon nanotubes even when used alone without an auxiliary dispersant (Example 6). However, when the ratio of the primary dispersant to the secondary dispersant is 1: 1 or more (Comparative Example 1) or when only the secondary dispersant is used without using the primary dispersant (Comparative Example 2), it is effective for dispersing carbon nanotubes, but the secondary dispersant is eluted to the surface of the specimen. It could be known. In addition, if the molecular weight of the auxiliary dispersant is too low, elution of the auxiliary dispersant occurs (Comparative Example 3), and if the molecular weight of the auxiliary dispersant is too high, the dispersion effect is reduced due to the decrease in wettability during the carbon nanotube dispersion treatment (Comparative Example 4). On the whole, the surface resistance reduction effect was larger when the dispersant mixture was used relatively (Examples 5 and 8). On the other hand, using polyethylene glycol (Example 9) or dimethyl ether (Example 10) instead of polyethylene methyl ether as an auxiliary dispersant did not differ significantly.

It was confirmed that excellent dispersion effects were also observed when polyethersulfone (Example 7) and polycarbonate (Example 8) were used as other polymers instead of m-PPO. This means that the dispersant composition of the present invention is not effective for any particular polymer.

Various modifications and variations can be made by those skilled in the art within the equivalent scope of the technical concept of the present invention and the claims to be described below.

When the carbon nanotubes treated with the dispersant composition of the present invention are melt-mixed with various polymers, carbon nanotubes are uniformly dispersed in the polymer as a dispersion medium to prepare a carbon nanotube polymer masterbatch or compound having greatly improved conductivity and overall physical and mechanical properties. In addition, when using a solvent as a dispersion medium can be prepared carbon nanotube coating liquid. The carbon nanotube powder dispersed by the dispersant composition for carbon nanotubes of the present invention can be applied in various ways in the carbon nanotube material market, which is not only excellent in its own characteristics but also needs sufficient dispersion in a matrix.

Claims (10)

A dispersant composition for carbon nanotubes comprising a polysiloxane-poly (ethylene / propylene glycol) graft copolymer represented by the following general formula (1) as a main dispersant and a polyethylene glycol compound represented by the following general formula (2) as an auxiliary dispersant:

(One)
Wherein R is a hydrogen atom or a methyl group, m is an integer from 0 to 50, n is an integer from 0 to 50, m + n is 0 to 50, x is an integer from 10 to 50, y is An integer from 10 to 35, and x + y is from 20 to 85.)

(2)
Wherein R is a hydrogen atom or a methyl group and n is an integer ranging from 11 to 110. The dispersing agent composition for carbon nanotubes of claim 1, wherein the polysiloxane-poly (ethylene / propylene glycol) copolymer and the polyethylene glycol compound are included in a weight ratio of 1: 1 to 5: 1. The dispersing agent composition for carbon nanotubes of claim 1, wherein the number average molecular weight of the graft copolymer is in the range of 5,000 to 50,000, and the graft ratio is 50 to 90%. According to claim 1, wherein the graft copolymer is a dispersion composition for carbon nanotubes, characterized in that the liquid has a viscosity of 200 to 2,500 cps at 25 ℃. The dispersing agent composition for carbon nanotubes of claim 1, wherein the polyethylene glycol compound has a number average molecular weight of 500 to 5,000. Carbon nanotube composite comprising a dispersant composition for carbon nanotubes according to any one of claims 1 to 5. The carbon nanotube composite according to claim 6, wherein the mixing weight ratio of the dispersant composition and the carbon nanotube is 0.1-30: 70-99.9. A polymer composite produced using the carbon nanotube composite according to claim 6. The method of claim 8, wherein the polymer is polyolefin, polyacrylonitrile butadiene styrene (ABS), polystyrene, polymethyl methacrylate (PMMA), nylon, polycarbonate, polyoxymethylene, polyethersulfone, polyphenylene oxide ( PPO), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyetherimide (PEI) and one or more selected from the group consisting of modified substances thereof Polymer composite material, characterized in that. Coating liquid prepared using the carbon nanotube composite according to claim 6.