WO2016071484A1

WO2016071484A1 - Composition for forming transparent conductive layer and method for preparing the same

Info

Publication number: WO2016071484A1
Application number: PCT/EP2015/075887
Authority: WO
Inventors: Young-Keun Kim; Beom-Jin CHOI
Original assignee: Solvay Sa
Priority date: 2014-11-07
Filing date: 2015-11-06
Publication date: 2016-05-12
Also published as: TW201623479A

Abstract

The present invention concerns compositions comprising at least one carbon nanotube, at least one dispersant, at least one silicone-based monomer and/or binder, and at least one solvent, and methods for making the same. The compositions according to the present invention can be used for forming a transparent conductive layer particularly useful as a transparent electrode, an antistatic layer, and/or an electromagnetic interference shield layer in a display device application.

Description

Composition for forming transparent conductive layer and method for preparing the same

This application claims priority to European patent application No.

14192189.0 filed on November 7, 2014, the whole content of the application being incorporated herein by reference for all purposes.

FIELD OF THE INVENTION

The present invention relates to a carbon nanotube (CNT) composition and to a layer made from said composition suitable for use as a transparent electrode, an antistatic layer, and/or an electromagnetic interference (EMI) shield layer for display device, such as liquid crystal display (LCD) device and organic light- emitting diode (OLED) device.

BACKGROUND OF THE INVENTION

Display devices, such as liquid crystal display (LCD) devices, are used for a television, a projector, a mobile phone, a PDA, a vehicle, etc., and such devices usually comprise plural transparent conductive layers for various purposes, including a transparent electrode, an antistatic layer, and an electromagnetic interference (EMI) shield layer. Conventional conductive materials for the transparent conductive layer in such display device are transparent conductive oxides (TCO), such as indium tin oxide (ITO), indium zinc oxide (IZO) and antimony tin oxide (ATO). The materials are typically deposited by using sputtering. However, this process is rather complicated and costly. Also, these materials are disadvantageous because many cracks may be generated upon their formation (lack of flexibility), and indium which is the main element of ITO and IZO is a limited resource that is becoming quickly exhausted these days.

Carbon nanotube (CNT) is one of the conductive materials which are the candidates to replace TCO in forming transparent conductor in electronics application.

Development of CNT composition which can be suitably used for forming a transparent conductive layer is desired in the art. DESCRIPTION OF THE INVENTION

The purpose of the present invention is to provide coating compositions having particular advantageous properties, which can be suitably used for forming a transparent electrode, an antistatic layer, and/or an EMI shield layer in electronic applications, such as in display devices. The compositions according to the present invention can be suitably used for forming a layer exhibiting an excellent thermal stability at high temperature, a satisfactory range of conductivity, and excellent hardness and transparency.

The present invention therefore relates to compositions comprising at least one carbon nanotube, at least one dispersant, at least one silicone -based monomer and/or binder, and at least one solvent, wherein pH of water solution comprising 1 wt % of the dispersant is less than 5.

Indeed, it has been surprisingly found that the compositions according to the present invention display superior stability at high temperature, such as at least 300°C. It has been also found that the compositions according to the present invention can attain strong adhesion to an underlying substrate, excellent hardness and transparency when processed to the layer in display devices. In addition, the compositions according to the present invention can satisfy a satisfactory range of conductivity without deteriorating other properties required in certain layer in display devices.

Further, the present invention provides transparent electrodes, antistatic layers, and/or EMI shield layers, which are particularly suitable for display devices, obtainable from the compositions according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

In the present invention, a carbon nanotube is understood to denote in particular fullerenes having cylindrical (or tubular) nanostructure, of which length(L)-to-diameter(D) ratio (L/D) is often at least 100. Examples of the carbon nanotube include single-wall carbon nanotubes (SWCNT), multi-wall carbon nanotubes (MWCNT), and derivatives thereof (e.g. carbon nanobuds). SWCNT is particularly preferred in the present invention. Without wishing to be bound by any theory, use of SWCNT in this application is believed to enable achieving required transparency as well as high conductivity, because of its shape. In the present invention, the length of the SWCNT is often no more than 10 micron, preferably no more than 5 micron.

In the present invention, a substrate is understood to denote in particular a solid, in particular a transparent solid on which a layer of material can be deposited using the composition according to the invention. Examples of such substrates include a glass substrate, and transparent solid polymers, for example polyethyleneterephthalate(PET), polyethylene naphthalene dicarboxylate, polycarbonate(PC), polyethersulfone(PES), polyimide(PI), cyclic olefin copolymer(COC), styrene copolymers, polyethylene, polypropylene, and any combination thereof. Preferably, the substrate is in the form of a sheet.

In the present invention, "alkyl groups" is understood to denote in particular a straight chain, branched chain, or cyclic hydrocarbon groups usually having from 1 to 20 carbon atoms, preferably having from 1 to 8 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

In the present invention, "alkoxy groups" is understood to denote in particular a straight chain, branched chain, or cyclic hydrocarbon group usually having from 1 to 20 carbon atoms, preferably from 1 to 8 carbon atoms, singularly bonded to oxygen (Alk-O-).

In the present invention, "aryl groups" is understood to denote in particular any functional group or substituent derived from an aromatic ring. In particular, the aryl groups can have 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms, in which some or all of the hydrogen atoms of the aryl group may or may not be substituted with other groups, especially alkyl groups, alkoxy groups, aryl groups, or hydroxyl groups. The aryl groups are preferably optionally substituted phenyl groups, naphthyl groups, anthryl group and phenanthryl group.

In the present invention, the carbon nanotube is typically used in an amount of 0.01 to 1 relative to a total weight of the composition. By comprising the carbon nanotube in the above range, the composition according to the present invention can exhibit good conductivity and coatability as well as transparency.

In the present invention, the composition comprises at least one silicone - based monomer and/or binder. Particularly, the silicone-based monomer and/or binder can be selected from the group consisting of trialkoxysilane,

trichlorosilane, tetrachlorosilane, aminosilane -based binders, tetraalkoxysilane- based binders, and any combination thereof. Preferable examples of the monomer and/or binder are tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), TEOS-based binder, TMOS-based binder and any combination thereof. More preferably, the composition according to the present invention comprises TEOS binder. In the present invention, the composition may comprise additional binder. The binder in the present invention may be an organic compound, an inorganic compound, or a hybrid compound thereof. Examples of the organic binder include polyesters, such as polyethylene terephthalate, polybutylene

terephthalate, and polyethylene naphthalate; polyimides, such as polyimide, and polyamideimide; polyamides, such as polyamide 6, polyamide 6, 6,

polyamide 12, and polyamide 11; fluororesins, such as polyvinylidene fluoride, polyvinyl fluoride, polytetrafluoroethylene, ethylenetetrafluoroethylene copolymer, and polychlorotrifluoroethylene; vinyl resins, such as polyvinyl alcohol, polyvinyl ether, polyvinyl butyral, polyvinyl acetate, and polyvinyl chloride; epoxy resin; oxetane resin; xylene resin; aramide resin; polyimide silicone; polyurethane; polyurea; melamine resin; phenol resin; polyether;

organosilicones; poly(ethylene oxide)s (PEO); acrylic resin, and their

copolymers.

In the present invention, the composition preferably comprises the silicone - based monomer and/or binder as a sole binder system or as a main binder system of the composition. Especially, when the layer to be formed by the composition of the present invention is to be deposited on glass substrate, this binder system is particularly preferred because it allows excellent hardness and adhesion to the substrate.

In the present invention, the binder is typically used in an amount of 1 to 30 wt %, preferably 3 to 20 wt %, more preferably 5 to 10 wt % relative to a total weight of the composition.

The composition according to the present invention further comprises at least one particular dispersant. Such dispersant is featured by showing pH of less than 5 when 1 wt % thereof is dissolved in water solution. Preferably, such pH is equal to or less than 4, more preferably equal to or less than 3. The pH is preferably at least 1, more preferably at least 2. The dispersant which can show the pH range from 2 to 3 is particularly preferred. This feature is believed to enable attaining an excellent compatibility between the CNT dispersion and the silicone-based binder solution without causing any substantial deterioration of the qualities of CNT (e.g. agglomeration of CNTs) upon mixing with the binder solution. Further, the selection of dispersant should also be made under the consideration to assure the compatibility with the solvent which is to be explained hereunder. In the present invention, the dispersant is preferably selected from those comprising at least one acid group selected from the group consisting of sulfonate, sulfate, phosphate groups, and any combination thereof. The dispersant comprising at least one phosphate group is particularly preferred.

More preferably, the dispersant is selected from the group consisting of alkyl phosphonates, alkyl ether phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene aryl ether phosphates, polyoxyethylene alkyl aryl ether phosphates, polyoxyethylene styrenated aryl ether phosphates,

polyoxyethylene alcohol ether phosphates, and any combination thereof.

Particular example of the dispersant comprising at least one sulfonate group includes polystyrene sulfonates, such as poly(4-styrenesulfonic acid) ("PSS"). Molecular weight (Mw) of the PSS may be from 1,000 to 200,000 mol/L.

Another specific type of the dispersant includes polymeric dispersant comprising at least one maleic acid group. Particular example thereof includes poly(methyl vinyl ether-a/t-maleic acid) which is available from Sigma- Aldrich.In the present invention, the dispersant is used in an amount of 0.01 to 1 wt % relative to a total weight of the composition.

In the present invention, the solvent in the composition according to the present invention is selected from the group consisting of water ; aliphatic alcohols, such as methanol, ethanol, isopropanol, butanol, n-propylalcohol, ethylene glycol, propylene glycol, butanediol, neopentyl glycol, 1,3-pentanediol, 1 ,4-cyclohexanedimethanol, diethyleneglycol, polyethelene glycol, polybutylene glycol, dimethylolpropane, trimethylolpropane, sorbitol, esterification products of the afore-mentioned alcohols ; aliphatic ketones, such as methyl cellosolve, propyleneglycol methylether, diacetone alcohol, ethylacetate, butylacetate, acetone and methylethylketone ; ethers such as tetrahydrofuran, dibutyl ether, mono- and polyalkylene glycol dialkyl ethers ; aliphatic carboxylic acid esters ; aliphatic carboxylic acid amides ; aromatic hydrocarbons ; aliphatic

hydrocarbons ; acetonitrile ; aliphatic sulfoxides ; and any combination thereof. Preferred solvents are water, isopropanol, ethylene glycol, propylene glycol methyl ether, propylene glycol methyl ether acetate, toluene, xylene, methyl ethyl ketone, dibutyl ether, butyl acetate, or any combination thereof.

In the present invention, the solvent is used in an amount of comprising the solvent in an amount of 68 to 98.98 wt %, preferably 78 to 96.98 wt %, more preferably 88 to 94.98 wt % relative to a total weight of the composition. By comprising the solvent in the above range, the composition according to the present invention can exhibit good coatability when processed to a layer.

In a further particular embodiment, the composition according to the present invention further comprises at least one additive selected from the group consisting of a conductive compound, a coupling agent, a surfactant, an inhibitor, a catalyst, an antioxidant agent, and any combination thereof.

In the present invention, a coupling agent is understood to function to aid an adhesion to a substrate when applied to the substrate. Such coupling agent can be selected, for example, from the group consisting of ammonia,

chlorosilane, monomeric aminosilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethyoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, vinyltrimethoxysilane,

vinyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, N-P-aminoethyl-y- aminopropyltrimethoxysilane, N-P-aminoethyl-Y-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane,

γ-acryloxypropyldimethoxysilane and any combination thereof. Preferred examples of the coupling agent are chlorosilane, monomeric amino silane, vinyltrimethoxysilane, and vinyltriethoxysilane.

In the present invention, a surfactant is understood to denote in particular a material that lowers the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid. The surfactant in the present invention preferably has a hydrophile lipophile balance (HLB) of 8 to 16, preferably 10 to 13. Preferred examples of the surfactant include BYK^® surfactants (obtainable from BYK Additives & Instruments), such as BYK^®-307, alkanesulfonates, betaines, alkylethoxylates, ethersulfates, and any combination thereof. More preferably, the surfactants are BYK^®-307, alkanesulfonates, and alkylethoxylates .

In the present invention, an inhibitor can be optionally added to the composition in order to keep the adequate extent of the polymerization. The examples of the inhibitor include hydroquinone, dialkylacetylenedicarboxylate, dimethylacetylenedicarboxylate, di ethyl enedicarboxylate,

dibutylacetylenedicarboxylate, metylbutylacetylenedicarboxylate,

methylethylacetylenedicarboxylate, and any combination thereof. Preferred inhibitors are hydroquinone, dialkylacetylenedicarboxylate, and

dimethylacetylenedicarboxylate. In the present invention, a catalyst can be used to accelerate a formation of binder from the respective monomer in the composition according to the present invention. Amines, organic or inorganic acids, metals or metal salts, peroxides, or any combination thereof can be used as the catalyst in the present invention. The non-limiting examples of the amines include ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine,triethylamine, n- propylamine, isopropylamine, di-n-propylamine, di-isopropylamine, tri-n- propylamine, n-butylamine, isobutylamine, di-n-butylamine, di-isobutylamine, tri-n-butylamine, n-pentylamine, di-n-pentylamine, tri-n-pentylamine, dicyclohexylamine, aniline, 2,4-dimethylpyridine, 4,4-trimethylenebis(l- methylpiperidine), 1 ,4-di-azabicyclo[2,2,2]octane, N,N-dimethylpiperazine, cis-2,6-dimethylpiperazine, trans-2,5-dimethylpiperazine,

4,4-methylenebis(cyclohexylamine), stearylamine, 1 ,3-di-(4-piperidyl)propane, Ν,Ν-dimethylpropanolamine, N,N- dimethylhexanolamine,

N,N-dimethyloctanolamine, Ν,Ν-diethylethanolamine, 1-piperidineethanol, 4-piperidinol, and any combination thereof. The non-limiting examples of organic or inorganic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, maleic acid, stearic acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, chloric acid, hypochlorous acid, and any combination thereof. The non-limiting examples of metals and metal salts include palladium, palladium acetate, palladium acetylacetonate, silver, silver acetylacetonate, platinum, platinum acetylacetonate, ruthenium, ruthenium acetylacetonate, ruthenium carbonyls, gold, copper, copper acetylacetonate, aluminum acetylacetonate, aluminum tris(ethylacetoacetate), and any

combination thereof. The non-limiting examples of peroxides include hydrogen peroxide, metal chlorides, organometallic compounds, such as ferrocenes and zirconocenes, and any combination thereof. Preferred examples of the catalyst in the present invention are 4,4-methylenebis(cyclohexylamine), acetic acid, hydrochloric acid, platinum, platinum acetylacetonate, hydrogen peroxide, and dicumyl peroxide.

In the present invention, examples of the antioxidant agent include citric acid, gallate esters, tocopherols, other phenol-based antioxidants, amine -based antioxidants, phosphorous-based antioxidants, sulfur-based antioxidants, sugars, and vitamins.

In an especially preferred embodiment, the composition according to the present invention comprises at least one SWCNT, at least one silicone -based binder, and at least one dispersant comprising phosphate group, in a mixed solvent comprising water and at least one alcohol.

In a particular embodiment of the present invention, the composition according to the present invention comprises at least one CNT, at least one silicone -based binder, and at least one PSS, in a mixed solvent comprising water and at least one alcohol.

In another particular embodiment of the present invention, the composition according to the present invention comprises at least one CNT, at least one silicone -based binder, and at least one polymeric dispersant comprising at least one maleic acid group, in a mixed solvent comprising water and at least one alcohol.

Another aspect of the present invention is related to method of

manufacturing a conductive coating composition. Such method comprises preparing a dispersion of carbon nanotube by using a dispersant wherein pH of the dispersion is less than 5; preparing a binder solution comprising at least one silicon-based monomer and/or binder, and at least one acid catalyst; and mixing the dispersion of carbon nanotube and the binder solution to obtain the conductive coating composition.

As to the nature and scope of each component (e.g. carbon nanotube, dispersant, silicon-based monomer and/or binder, acid catalyst, etc.), reference can be made to the explanation given in the foregoing sections.

In the present invention, the dispersion of carbon nanotube may be prepared by using at least one mechanical dispersion method. Examples of the mechanical dispersion method include ultrasonication, high-shear-stress dispersion, and ball milling, but the present invention is not limited thereto.

Ultrasonication may break up nanotube aggregates in solution processing of CNTs in a convenient and practical manner. When ultrasonic waves pass through a liquid medium, a large number of microbubbles form, grow, and collapse in very short times, about a few microseconds. Ultrasonication generates alternating low-pressure and high-pressure waves in liquids, leading to the formation and violent collapse of small vacuum bubbles.

The principle of high-shear-stress dispersion is the shear stress exerted on CNTs during mixing that overcomes electrostatic and van der Waals interactions between CNTs and results in the breakup of agglomerates. High-shear- stress dispersion of CNTs can be conducted with different apparatus including a high- shear homogenizer, singe or twin-screw extruder, injection-molding machine and micro fluidic channels.

Ball milling is a mechanical dispersion method which generates local high- impact areas between the balls resulting in a random crushing of the materials. Ball mills can be designed in horizontal or vertical construction. Much higher quantities of dispersed samples can be produced by ball milling compared to other dispersion technique, which make this method very practical.

For more details of the CNT dispersion method, reference can be made to [Frank K. Ko et al., Introduction to Nanofiber Materials, DATE

PUBLISHED July 2014, ISBN: 9780521879835] and [A. Paipetis et al, Carbon Nanotube Enhanced Aerospace Composite Materials: A New Generation of Multifunctional Hybrid Structural Composites_^ Springer Science & Business Media, 14 Sep 2012 - Technology & Engineering].

In the present invention, ultrasonication method is preferably used in preparing the dispersion of CNT using the at least one dispersant.

In the present invention, a difference of pH between the dispersion of carbon nanotube and the binder solution is preferably equal to or less than 2, in particular equal to or less than 1.

The method of manufacturing a conductive coating composition according to the present invention preferably comprises contacting a dispersion of carbon nanotube of which pH is from 1.5 to 3 with the binder solution comprising at least one silicon-based monomer and/or binder of which pH is from 1.5 to 3. More preferably, the method comprises contacting a dispersion of SWCNT with at least one PSS wherein pH of the dispersion is from 1.5 to 3 with a solution of at least one silicon-based monomer and/or binder wherein pH of the solution is from 1.5 to 3. Alternatively, the method comprises contacting a dispersion of SWCNT with at least one dispersant comprising at least one dispersant comprising at least one phosphate group wherein pH of the dispersion is from 1.5 to 3 with a solution of at least one silicon-based monomer and/or binder wherein pH of the solution is from 1.5 to 3.

Further aspect of the present invention concerns a layer obtainable by using the composition according to the present invention. The layer according to the present invention can be used as a transparent conductor in electronic devices. More preferably, such layer functions as a transparent electrode, an antistatic layer, and/or an electromagnetic interference (EMI) shield layer in display device. The transparent electrode in the present invention is understood to denote any type of electrode used in electronics devices, in particular display devices. Examples thereof include common electrode, pixel electrode, electrodes included in thin-film transistor (TFT), such as gate electrode, scanning electrode, and data (signal) electrode, and optional electrodes, such as segment electrode, and chevron electrode.

It has been surprisingly found that the layer according to the present invention exhibits an excellent thermal stability even at high temperature of at least 200°C, preferably at least 230°C, more preferably at least 300°C, still more preferably at least 350°C and less than 400 °C while showing a good flexibility, a satisfactory range of conductivity, and great hardness and transparency.

The layer can be formed by applying the compositions of the present invention on the substrate, in particular on a surface of glass substrate. Such application can be brought about for example using laser etching, wetting, such as dipping, printing, such as gravure printing and inkjet printing, coating, such as spin coating, bar coating, slit coating, spray coating, roll coating, and spreading, or deposition. The thickness of the layer on the substrate is preferably from 100 to 10,000 A, more preferably 3,000 to 4,000 A. After applying the composition on the substrate, the layer can be formed for example by curing. Typical temperatures for the curing are from 25 to 150°C, preferably 100 to 150°C. Typical curing time is from 5 to 30 min, preferably 10 to 30 min.

A still further aspect of the present invention concerns an electronic device at least comprising the layer according to the present invention. Representative examples of the electronic device in the present invention include display devices, such as LCD and OLED.

An additional aspect of the present invention concerns a process of manufacturing a layer, which is obtainable by using the composition according to the present invention.

The process for the manufacture of the layer preferably comprises (a) evenly spreading the composition according to the present invention on a surface of a substrate and (b) curing the composition spread on the surface.

Thusly-formed layer according to the present invention has generally a

3 12

sheet resistance of 10 to 10 ohm/square. If the layer is intended as the antistatic layer according to the present invention, it generally has a sheet resistance of 10 7 to 1012 ohm/square. Alternatively, the antistatic layer according

3 11

to the present invention has a sheet resistance of 10 to 10 ohm/square, 4 8

preferably 10 to 10 ohm/square. In case the layer is intended as the EMI shield, it generally has a sheet resistance of 10³ to 10⁶ ohm/square. Also, the layer has generally a pencil hardness of equal to or more than 7 H, more preferably equal to or more than 9 H, which satisfies the requirement as a transparent conductive layer in display device, especially LCD device.

Should the disclosure of any patents, patent applications, and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.

The following examples illustrate the invention in further detail without however limiting it.

Examples

Example 1 : Preparation of Conductive Coating Solution

Example 1-1 : Preparation of CNT dispersion

0.1 wt % of SWCNT (obtainable from KH Chemical) is dispersed in water solution by using 0.1 wt % of anionic dispersant containing phosphate group under vigorous stirring. The pH of the dispersion is 2-3.

Example 1-2 : Preparation of binder solution

11 wt % of TEOS monomer (obtainable from Merck) and 2 wt % of acetic acid catalyst are mixed in water/isopropanol (1 : 1) solvent system under stirring.

The pH of the binder solution is 2~3.

Example 1 -3 : Preparation of CNT coating solution

The binder solution prepared in accordance to the example 1-2 is slowly added to the CNT dispersion prepared according to the example 1-1 under stirring so to obtain the coating solution comprising 0.05 wt % of SWCNT, 5.5 wt % of TEOS binder, 0.05 wt % of dispersant, and remainder of isopropanol and water.

Example 2 : Evaluation of coating films made of Conductive Coating Solution The conductive coating solution according to Example 1 is supplied to a spin coater, and coated with rotation speed at 300 rpm for 3 seconds, 1000 rpm for 15 seconds, and 300 rpm for 3 seconds at a room temperature. The formed coating film using the conductive coating solution is treated in dry oven at a temperature of about 140°C for 10 min.

A sheet resistance, transmittance, surface hardness, thermal stability, and sheet uniformity of the coating film are evaluated, and summarized as below : - Sheet resistance : measured using 2-point probe - Transmittance : measured using UV-VIS spectrometer at 550 nm

- Surface hardness : measured using pencil hardness test method

- Thermal stability : change of sheet resistance after exposing the layer for 30 minutes at temperature of 350°C

- Sheet uniformity : deviation of resistance values at different points of the coating film were measured

Table 1 : Evaluation Results

Example 1

Resistance

10⁵

(ohm/square)

Transmittance over 98 %

Hardness 9 H

Thermal stability Less than 10⁶

Claims

C L A I M S

1. A composition comprising at least one carbon nanotube, at least one dispersant, at least one silicone -based monomer and/or binder, and at least one solvent, wherein pH of water solution comprising 1 wt % of the dispersant is less than 5.

2. The composition according to claim 1, wherein the pH is equal to or less than 4, in particular equal to or less than 3.

3. The composition according to claim 1 or 2, wherein the carbon nanotube is single-wall carbon nanotube (SWCNT).

4. The composition according to any one of claims 1 to 3, wherein the dispersant comprises at least one acid group selected from the group consisting of sulfonate, sulfate, phosphate groups, and any combination thereof, in particular phosphate group.

5. The composition according to claim 4, wherein the dispersant is selected from the group consisting of alkyl phosphonates, alkyl ether phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene aryl ether phosphates, polyoxyethylene alkyl aryl ether phosphates, polyoxyethylene styrenated aryl ether phosphates, polyoxyethylene alcohol ether phosphates, and any

combination thereof.

6. The composition according to any one of claims 1 to 5, wherein the binder comprises at least one thermosetting silicone-based monomer and/or binder selected from the group consisting of trialkoxysilane, trichlorosilane, tetrachlorosilane, aminosilane -based binders, tetraalkoxysilane -based binders, and any combination thereof, especially tetraethoxysilane (TEOS),

tetramethoxysilane (TMOS), TEOS-based binder, TMOS-based binder, and any combination thereof.

7. The composition according to any one of claims 1 to 6, wherein the solvent is selected from the group consisting of water ; aliphatic alcohols, such as methanol, ethanol, isopropanol, butanol, n-propylalcohol, ethylene glycol, propylene glycol, butanediol, neopentyl glycol, 1,3-pentanediol,

1 ,4-cyclohexanedimethanol, diethyleneglycol, polyethelene glycol, polybutylene glycol, dimethylolpropane, trimethylolpropane, sorbitol, esterification products of the afore-mentioned alcohols ; aliphatic ketones, such as methyl cellosolve, propyleneglycol methylether, diacetone alcohol, ethylacetate, butylacetate, acetone and methylethylketone ; ethers such as tetrahydrofuran, dibutyl ether, mono- and polyalkylene glycol dialkyl ethers ; aliphatic carboxylic acid esters ; aliphatic carboxylic acid amides ; aromatic hydrocarbons ; aliphatic

hydrocarbons ; acetonitrile ; aliphatic sulfoxides ; and any combination thereof.

8. The composition according to any one of claims 1 to 7, comprising the carbon nanotube in an amount of 0.01 to 1 wt % relative to a total weight of the composition.

9. The composition according to any one of claims 1 to 8, comprising the binder in an amount of 1 to 30 wt %, preferably 3 to 20 wt %, more preferably 5 to 10 wt % relative to a total weight of the composition.

10. The composition according to any one of claims 1 to 9, comprising the dispersant in an amount of 0.01 to 1 wt % relative to a total weight of the composition.

11. A method of manufacturing a conductive coating composition, comprising: preparing a dispersion of carbon nanotube by using a dispersant wherein pH of the dispersion is less than 5; preparing a binder solution comprising at least one silicon-based monomer and/or binder, and at least one acid catalyst; and mixing the dispersion of carbon nanotube and the binder solution to obtain the conductive coating composition.

12. The method according to claim 11, wherein a difference of pH between the dispersion of carbon nanotube and the binder solution is equal to or less than 2, in particular equal to or less than 1.

13. A conductive transparent layer obtainable by using the composition according to any one of claims 1 to 10.

14. The layer according to claim 13, which functions as a transparent electrode, an antistatic layer, and/or an electromagnetic interference (EMI) shield layer.

15. An electronic device at least comprising the layer according to claim 13 or 14.