Paste composition comprising hydrophilically modified carbon-based material, preparation method therefor, method for preparing coating composition, and coating composition prepared thereby

Abstract

The present invention relates to a paste composition comprising a hydrophilically modified carbon-based material, a preparation method therefor, a method for preparing a coating composition, and a coating composition prepared thereby. The hydrophilically modified carbon-based material of the present invention has hydrophilic properties through surface functionalization and chemical bonding processes, thereby exhibiting improved moisture adsorption and absorption abilities, and being capable of exhibiting improved moisture adsorption and absorption abilities and moisture spreading ability through surface pore control. Thus, a paste composition comprising same can exhibit increased stability and, upon coating onto various substrates, can exhibit excellent surface hydrophilicity and hygroscopicity. Therefore, those comprising the composition of the present invention can be actively used not only in heat dissipation industries that require humidity control and evaporation rate control but also in various industrial fields that require a coating solution.

Description

A paste composition comprising a hydrophilically modified carbon-based material, a method for manufacturing the same, a method for manufacturing a coating composition, and a coating composition manufactured therefrom.

[0001] This study was conducted under the Gyeonggi-do Energy Innovation Technology Support Project (2023-2324-001).

[0002] [Acknowledgement]

[0003] This research was supported by a grant (2023-2324-001) from Gyeonggi Energy Innovation Technology Support Project funded by Gyeonggi Province.

[0004] The present invention, derived from the study, relates to a paste composition comprising a hydrophilically modified carbon-based material, a method for manufacturing the same, a method for manufacturing a coating composition, and a coating composition manufactured therefrom.

[0005] In modern industry, there is a continuously increasing demand for technologies capable of more precisely controlling material properties in various fields, such as electronic devices, energy storage devices, and high-durability composite materials. Materials used in these fields must maintain stable performance over long periods even in high-temperature and high-humidity environments; to achieve this, it is necessary to appropriately control surface properties, such as hydrophilicity and hygroscopicity, as well as surface conductivity. In particular, electronic components and energy storage devices must control wetting properties while maintaining surface conductivity to operate stably in high-temperature and high-humidity environments. These wetting properties significantly affect the electrical performance and durability of components and are essential to prevent performance degradation that may occur in high-humidity environments.

[0006] Furthermore, surface properties of composite materials, particularly their ability to control wetting, are becoming increasingly important in the construction, medical, and automotive industries. Since construction materials are highly likely to be exposed to indoor and outdoor environments for extended periods, controlling the hydrophilicity and hygroscopicity of their surfaces can contribute to maintaining the durability and stability of structures. Medical devices and automotive components are also exposed to diverse environments, and controlling wetting properties plays an essential role in ensuring long-term reliability and maintaining performance. Consequently, these industrial sectors require improvements in the performance of pastes capable of controlling the wetting properties of material surfaces.

[0007] However, while conventional paste technologies utilizing carbon-based materials possess advantages such as high conductivity, strength, and durability, they exhibit limitations in terms of surface hydrophilicity and hygroscopicity. Commonly used carbon-based materials, particularly non-oxidized graphene, possess excellent electrical properties but have the disadvantage of low affinity for water due to their highly hydrophobic surfaces. Due to these characteristics, they fail to exhibit sufficient hygroscopic performance when coated on various substrates, leading to limitations in applications requiring moisture control. For example, when such carbon-based pastes are applied to electronic components, if the surface does not absorb moisture sufficiently, there is a possibility that the component's performance will degrade or its lifespan will be shortened in long-term high-temperature and high-humidity environments. Even when used in composite materials, the lack of hydrophilicity reduces adhesion to the substrate, raising concerns about weakened durability.

[0008] Accordingly, there is an urgent need for research and technological development to develop a carbon-based material-based paste applicable to various substrates and having excellent hydrophilicity and hygroscopicity, a method for manufacturing a coating composition containing the same, and a coating composition manufactured therefrom.

[0009] [Prior Art Literature]

[0010] [Patent Literature]

[0011] Patent Document 1: Korean Published Patent Application No. 10-2022-0095749 (July 7, 2022)

[0012] In order to solve the above problem, one aspect of the present invention provides a paste composition comprising a polymer binder; a hydrophilically modified carbon-based material; and a dispersant, wherein the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material is 10:1 to 2:1.

[0013] In addition, the present invention aims to provide a paste composition characterized by comprising, based on 100 parts by weight of the total, 50 to 80 parts by weight of a polymer binder, 10 to 30 parts by weight of a hydrophilically modified carbon-based material, and 0.1 to 25 parts by weight of a dispersant.

[0014] In addition, the present invention aims to provide a paste composition in which the hydrophilically modified carbon-based material is prepared by the following steps: (a) mechanically treating a carbon raw material to produce a carbon-based material having a D50 of 4 μm to 10 μm when analyzed by a particle size analyzer; (b) mixing the prepared carbon-based material with a hydrophilic polymer solution; and (c) stirring.

[0015] In addition, the present invention aims to provide a paste composition characterized in that the carbon raw material is one or more selected from the group consisting of graphite, graphene, graphene oxide, graphene reduction, non-oxidized graphene, graphene nanoplatelets, carbon black, and carbon nanotubes, or a mixture of one or more selected types.

[0016] In addition, the present invention aims to provide a paste composition characterized in that the dispersant is one or more selected from the group consisting of water-based dispersants, oil-based dispersants, amphiphilic dispersants, ionic surfactants, nonionic surfactants, additives, thickeners, and emulsifiers, or a mixture of one or more selected types.

[0017] In addition, the present invention aims to provide a method for preparing a paste composition comprising: a first step of preparing a hydrophilically modified carbon-based material; a second step of mixing a polymer binder with the hydrophilically modified carbon-based material; and a third step of adding a dispersant to the mixed hydrophilically modified carbon-based material and polymer binder.

[0018] In addition, the present invention aims to provide a method for preparing a paste composition, characterized in that the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material is 10:1 to 2:1.

[0019] In addition, the present invention aims to provide a method for preparing a paste composition, wherein the first step of preparing the hydrophilically modified carbon-based material comprises: (a) a step of preparing a carbon-based material having a D50 of 4 μm to 10 μm when analyzed by a particle size analyzer by mechanically treating a carbon raw material; (b) a step of mixing the carbon-based material with a hydrophilic polymer solution; and (c) a step of stirring.

[0020] In addition, the present invention aims to provide a method for preparing a paste composition, wherein the second step of mixing a polymer binder with the hydrophilically modified carbon-based material is to mix by stirring at 500 rpm to 1000 rpm for 10 minutes to 60 minutes.

[0021] In addition, the present invention aims to provide a method for preparing a coating composition comprising a first step of preparing a paste; and a second step of mixing a polymer binder, wherein the mixing ratio of the paste and the polymer binder is 1:1 to 1:5.

[0022] In addition, the present invention aims to provide a method for preparing a coating composition, further comprising a third step of adding a carbon-based material to the mixed paste and polymer binder.

[0023] In addition, the present invention comprises, in the first step of manufacturing the paste, a step of manufacturing a hydrophilically modified carbon-based material; and a step of mixing a polymer binder with the hydrophilically modified carbon-based material; The present invention provides a method for preparing a coating composition comprising the step of adding a dispersant; wherein the step of mixing a polymer binder with the hydrophilically modified carbon-based material is mixed by stirring at 500 rpm to 1000 rpm for 10 minutes to 60 minutes, wherein the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material is 10:1 to 2:1, and the carbon raw material is characterized by being one or more selected from the group consisting of graphite, graphene, oxidized graphene, reduced graphene, non-oxidized graphene, graphene nanoplatelets, carbon black, and carbon nanotubes, or a mixture of one or more selected types, and the dispersant is characterized by being one or more selected from the group consisting of water-based dispersants, oil-based dispersants, amphiphilic dispersants, ionic surfactants, non-ionic surfactants, additives, thickeners, and emulsifiers, or a mixture of one or more selected types.

[0024] In addition, the present invention aims to provide a coating composition prepared by the aforementioned method for preparing a coating composition.

[0025] In addition, the present invention aims to provide a coating method comprising the steps of: applying the coating composition to a substrate surface; and forming a coating layer on the substrate surface; and additionally comprising the step of drying at 100°C to 300°C for 5 to 60 minutes.

[0026] To solve the above problem, the present invention,

[0027] A paste composition comprising a polymer binder; a hydrophilically modified carbon-based material; and a dispersant, wherein the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material is 10:1 to 2:1.

[0028] In addition, the present invention provides a paste composition characterized by comprising, based on 100 parts by weight of the total, 50 to 80 parts by weight of a polymer binder, 10 to 30 parts by weight of a hydrophilically modified carbon-based material, and 0.1 to 25 parts by weight of a dispersant.

[0029] In addition, the present invention provides a paste composition in which the hydrophilically modified carbon-based material is prepared by the steps of: (a) mechanically treating a carbon raw material to produce a carbon-based material having a D50 of 4 μm to 10 μm when analyzed by a particle size analyzer; (b) mixing the prepared carbon-based material with a hydrophilic polymer solution; and (c) stirring.

[0030] In addition, the present invention provides a paste composition characterized in that the carbon raw material is one or more selected from the group consisting of graphite, graphene, graphene oxide, graphene reduction, non-oxidized graphene, graphene nanoplatelets, carbon black, and carbon nanotubes, or a mixture of one or more selected types.

[0031] In addition, the present invention provides a paste composition characterized in that the dispersant is one or more selected from the group consisting of water-based dispersants, oil-based dispersants, amphiphilic dispersants, ionic surfactants, nonionic surfactants, additives, thickeners, and emulsifiers, or a mixture of one or more selected types.

[0032] In addition, the present invention provides a method for preparing a paste composition comprising: a first step of preparing a hydrophilically modified carbon-based material; a second step of mixing a polymer binder with the hydrophilically modified carbon-based material; and a third step of adding a dispersant to the mixed hydrophilically modified carbon-based material and the polymer binder.

[0033] In addition, the present invention provides a method for preparing a paste composition, characterized in that the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material is 10:1 to 2:1.

[0034] In addition, the present invention provides a method for preparing a paste composition, wherein the first step of preparing the hydrophilically modified carbon-based material comprises: (a) a step of preparing a carbon-based material having a D50 of 4 μm to 10 μm when analyzed by a particle size analyzer by mechanically treating a carbon raw material; (b) a step of mixing the carbon-based material with a hydrophilic polymer solution; and (c) a step of stirring.

[0035] In addition, the present invention provides a method for preparing a paste composition, wherein the second step of mixing a polymer binder with the hydrophilically modified carbon-based material is to mix by stirring at 500 rpm to 1000 rpm for 10 minutes to 60 minutes.

[0036] In addition, the present invention provides a method for preparing a coating composition comprising a first step of preparing a paste; and a second step of mixing a polymer binder, wherein the mixing ratio of the paste and the polymer binder is 1:1 to 1:5.

[0037] In addition, the present invention provides a method for preparing a coating composition, further comprising a third step of adding a carbon-based material to the mixed paste and polymer binder.

[0038] In addition, the present invention comprises, in the first step of manufacturing the paste, a step of manufacturing a hydrophilically modified carbon-based material; and a step of mixing a polymer binder with the hydrophilically modified carbon-based material; The present invention provides a method for preparing a coating composition comprising the step of adding a dispersant; wherein the step of mixing a polymer binder with the hydrophilically modified carbon-based material is mixed by stirring at 500 rpm to 1000 rpm for 10 minutes to 60 minutes, wherein the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material is 10:1 to 2:1, and the carbon raw material is characterized by being one or more selected from the group consisting of graphite, graphene, oxidized graphene, reduced graphene, non-oxidized graphene, graphene nanoplatelets, carbon black, and carbon nanotubes, or a mixture of one or more selected types, and the dispersant is characterized by being one or more selected from the group consisting of water-based dispersants, oil-based dispersants, amphiphilic dispersants, ionic surfactants, non-ionic surfactants, additives, thickeners, and emulsifiers, or a mixture of one or more selected types.

[0039] In addition, the present invention provides a coating composition prepared by the method for preparing a coating composition described above.

[0040] In addition, the present invention provides a coating method comprising the steps of: applying the coating composition to a substrate surface; and forming a coating layer on the substrate surface; and additionally comprising the step of drying at 100°C to 300°C for 5 to 60 minutes.

[0041] The present invention provides a paste composition comprising a hydrophilically modified carbon-based material, a method for manufacturing the same, a method for manufacturing a coating composition, and a coating composition manufactured therefrom.

[0042] The modified carbon-based material of the present invention acquires hydrophilic properties through surface functionalization and chemical bonding processes, thereby enhancing moisture adsorption and absorption capabilities. Furthermore, surface pore control improves moisture adsorption and absorption capabilities as well as moisture spreading ability. In particular, the hydrophilic polymer maintains a constant spacing between particles, increasing the stability of the paste composition, and exhibits excellent surface hydrophilicity and hygroscopicity when coated on various substrates. Thus, the composition of the present invention provides characteristics suitable for various industrial fields, including the heat dissipation industry, which requires humidity control and evaporation rate control.

[0043] Furthermore, the coating composition according to the present invention exhibits high hygroscopicity, hydrophilicity, and spreadability that rapidly absorb and spread water droplets by including a hydrophilically modified carbon-based material, a polymer binder, and a dispersant in an optimal mixing ratio. In addition, it improves moisture adsorption and absorption capabilities and moisture spreadability performance through surface pore control. These characteristics enable the coating layer to maintain stable performance even in humid environments and provide strong adhesion by significantly improving the peel strength between the coating film and the substrate. As a result, the coating composition of the present invention can maintain excellent durability and reliability even with a thin coating film across various industries, making it suitable for use as a coating solution in diverse environmental conditions.

[0044] The attached drawings are intended to explain the contents of the present invention in more detail to those skilled in the art, and the technical concept of the present invention is not limited thereto.

[0045] FIG. 1 is a diagram of the manufacturing process of the paste composition and the coating composition of the present invention.

[0046] Figure 2 is a figure comparing the results of measuring the water droplet contact angle of a 600 μm SUS substrate coated with the paste composition and the coating composition of the present invention.

[0047] Figure 3 is a figure comparing the results of measuring the water droplet contact angle of a 60㎛ SUS substrate coated with the paste composition and the coating composition of the present invention.

[0048] Figure 4 is a figure comparing the difference in viscosity according to the composition of the paste composition and the coating composition of the present invention.

[0049] Figure 5 is a figure comparing the difference in peel strength of a coating film according to the composition of the paste composition and the coating composition of the present invention.

[0050] Hereinafter, a paste composition comprising a hydrophilically modified carbon-based material according to the present invention, a method for manufacturing the same, a method for manufacturing a coating composition, and a coating composition manufactured therefrom will be described in detail; however, the paste composition comprising the hydrophilically modified carbon-based material, the method for manufacturing the same, the method for manufacturing a coating composition, and the coating composition manufactured therefrom are not limited by the following description.

[0051]

[0052] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the present invention, and the present invention is defined only by the scope of the claims.

[0053] The terms used in this specification are for describing embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. The terms "comprises" and / or "comprising" used in this specification do not exclude the presence or addition of one or more other components in addition to the components mentioned. Throughout the specification, the same reference numerals refer to the same components, and "and / or" includes each of the mentioned components and all combinations of one or more. Although terms such as "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical scope of the invention.

[0054] Unless otherwise defined, all terms used herein (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0055] Spatially relative terms such as "below," "beneath," "lower," "above," and "upper" may be used to facilitate the description of the relationship between one component and other components as illustrated in the drawings. Spatially relative terms should be understood as encompassing different orientations of components during use or operation, in addition to the orientations depicted in the drawings. For example, if a component depicted in a drawing is inverted, a component described as "below" or "beneath" of another component may be placed "above" of that component. Therefore, the exemplary term "below" may encompass both the lower and upper directions. Components may also be oriented in other directions, and accordingly, spatially relative terms may be interpreted according to the orientation.

[0056]

[0057] The present invention relates to a paste composition comprising a polymer binder, a hydrophilically modified carbon-based material, and a dispersant.

[0058] In addition, the present invention relates to a method for preparing a coating composition comprising a first step of preparing a paste; and a second step of mixing a polymer binder, wherein the mixing ratio of the paste and the polymer binder is 1:1 to 1:5.

[0059] In addition, the present invention relates to a coating composition comprising a paste; a polymer binder; and a hydrophilically modified carbon-based material.

[0060] The paste of the present invention comprises, but is not limited to, a polymer binder, a hydrophilically modified carbon-based material, and a dispersant.

[0061] The polymer binder of the present invention combines with a hydrophilically modified carbon-based material to provide adhesiveness and bonding strength to the paste. Specifically, the polymer binder combines with the hydrophilically modified carbon-based material to help the paste composition be evenly distributed and maintain a stable form, thereby providing excellent adhesion and durability to the surface of the substrate to which the paste is applied.

[0062] The above polymer binder may be an epoxy binder, a modified epoxy binder, a polyurethane binder, a polyester binder, an acrylic binder, etc. Specifically, polyacrylamide (PAM), polyvinyl alcohol (PVA), polyurethane, phenolic resins, silane coupling agents, polycarboxylic acids, urea-formaldehyde resin, alkyl cellulose, polyaniline, and preferably, an epoxy binder may be used.

[0063] Specifically, the present invention relates to a coating composition comprising an epoxy binder and a hydrophilically modified carbon-based material. By using the epoxy binder, strong adhesion and excellent chemical resistance are provided, enabling the formation of a stable coating layer on various substrates. Furthermore, the composition of the present invention exhibits excellent moisture barrier properties and thermal stability, maintaining its physical properties without change even in high humidity and high temperature environments. In addition, the epoxy binder possesses electrical insulation properties, making it suitable for coating electronic components. Moreover, when combined with the hydrophilic carbon-based material, it enables uniform dispersion, thereby improving the performance and consistency of the coating layer.

[0064] The hydrophilically modified carbon-based material of the present invention is manufactured by the steps of: (a) mechanically treating a carbon raw material to produce a carbon-based material having a D50 of 4 μm to 10 μm when analyzed by a particle size analyzer; (b) mixing the produced carbon-based material with a hydrophilic polymer solution; and (c) stirring.

[0065] In addition, the stirring step (c) above may be performed at a temperature of 40°C to 80°C at 200 rpm to 300 rpm, and these conditions may provide a reaction environment optimized for hydrophilic modification of the carbon-based material.

[0066] Here, if the reaction temperature is set to less than 40℃, the viscosity of the polymer binder is not properly maintained, resulting in reduced mixing homogeneity and an excessively slow reaction rate, which makes it highly likely that the reaction will not proceed properly. Consequently, aggregation may occur between the carbon-based material and the polymer binder, which may lead to a deterioration in the quality of the composition.

[0067] Conversely, at temperatures exceeding 80°C, the volatility of the polymer binder increases, so viscosity is not maintained, and the carbon-based material may have difficulty forming a stable dispersion state as it is solidified by the polymer binder.

[0068] Therefore, by performing stirring at a temperature of 40°C to 80°C, the viscosity of the polymer binder can be maintained, and homogeneous mixing and stable modification with the carbon-based material can be enabled.

[0069] The above carbon raw materials are not particularly limited, but may be one or more selected from the group consisting of graphite, graphene, graphene oxide, graphene reduction, non-oxidized graphene, graphene nanoplatelets, carbon black, and carbon nanotubes, or a mixture of one or more selected types, and preferably, non-oxidized graphene may be used.

[0070] Specifically, the present invention utilizes non-oxidized graphene as a carbon raw material, thereby ensuring superior electrical and thermal conductivity compared to other carbon raw materials (e.g., oxidized graphene, graphene nanoplatelets). Since non-oxidized graphene does not undergo an oxidation process, it maintains its inherent conductivity and improves the physical properties of the coating layer by providing strong adhesion and uniform dispersibility when combined with an epoxy binder. Furthermore, non-oxidized graphene exhibits superior durability compared to oxidized graphene due to its high chemical stability, and when modified to be hydrophilic, it demonstrates excellent wetting characteristics, thereby increasing adhesion to the substrate. Accordingly, the coating composition of the present invention using non-oxidized graphene provides enhanced effects in terms of conductivity, durability, and adhesion.

[0071] The above mechanical treatment refers to a process of applying physical force to control the particle size, shape, and surface area of ​​the material, particularly in the present invention, and methods such as ball milling, ultrasonic treatment, dry milling, or rolling milling may be used.

[0072] Specifically, in the present invention, dry milling was performed using an Air Jet Mill under conditions of 3 bar to 5 bar and 3000 rpm to 8000 rpm, but is not particularly limited thereto.

[0073] The analysis performed by the above particle size analyzer evaluates the size and distribution of powder or dispersed particles, and methods such as laser diffraction, dynamic light scattering (DLS), image analysis, sieve analysis, or sedimentation analysis may be used.

[0074] Specifically, the present invention analyzes particle size by laser diffraction analysis, and the hydrophilically modified carbon-based material of the present invention has a particle size of 4㎛ to 15㎛, 4㎛ to 10㎛, 4㎛ to 8㎛, or 4㎛ to 6㎛ based on the D50 value, and the carbon-based material having a particle size within the above range can maximize the reduction rate of the surface water droplet contact angle, thereby having the effect of increasing affinity with water.

[0075] The hydrophilic polymer of the present invention may use one or more selected from the group consisting of polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyetherimide (PEI), and polyacrylic acid (PAA), but is not particularly limited thereto. For example, the hydrophilic polymer may be replaced with hydrophilic liquids in liquid form, and the hydrophilic liquids may include ethylene glycol, diethylene glycol, hydroxy peroxide, etc.

[0076] In the present invention, polyethylene glycol (PEG) was used as the hydrophilic polymer. Polyethylene glycol (PEG) can exist in a liquid state among hydrophilic polymers, allowing it to easily bond to the surface of carbon-based materials and easily penetrate between the lattice layers of carbon-based materials, thereby enabling surface modification of carbon-based materials even with a simple process. On the other hand, since other hydrophilic polymers other than polyethylene glycol (PEG) are in powder form, it is difficult to carry out the process for modifying the surface of carbon-based materials while they are dissolved in a solvent; therefore, polyethylene glycol (PEG) is more suitable for use than other hydrophilic polymers. Furthermore, it is difficult to select a suitable solvent that simultaneously dissolves the hydrophilic polymer and the carbon-based material, and if additional solvents or other separate processes are added, manufacturing costs increase and environmental pollution problems may arise.

[0077] As a dispersant of the present invention, a modified polyacrylate blocked polymer may be mainly used, and the dispersant may be one or more selected from the group consisting of polyacrylate-based dispersants, polyurethane-based dispersants, styrene-based dispersants, alkyl vinyl ether dispersants and fatty acid-based dispersants, or a mixture of one or more selected types, but is not limited thereto.

[0078] Preferably, polyurethane-based dispersants and polyacrylate-based dispersants may be used, and more preferably, polyacrylate-based dispersants may be used.

[0079] In addition, the above-mentioned dispersant may be one or more selected from the group consisting of water-based dispersants, oil-based dispersants, amphiphilic dispersants, ionic surfactants, nonionic surfactants, additives, thickeners, and emulsifiers, or a mixture of one or more selected types, but is not limited thereto.

[0080] Specifically, polyvinyl alcohol (PVA), polyethylene glycol (PEG), polyacrylic acid (PAA), polyvinylpyrrolidone (PVP), polysorbate (Tween), sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), Triton X-100, lecithin, acetylene glycol, sodium silicate (water-soluble glass), phosphate (sodium tripolyphosphate, TSPP), aluminum sulfate, magnesium silicate, calcium carbonate, titanium oxide (TiO₂), gum arabic, cellulose derivatives (CMC, HPMC, etc.), gelatin, chitosan, etc. may be used, but are not limited thereto.

[0081] The paste composition of the present invention is characterized in that the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material is 10:1, preferably 6:1, and more preferably 3:1.

[0082] In addition, the paste of the present invention is characterized in that the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material is 10:1, preferably 7:1, and more preferably 5:1.

[0083] When a polymer binder and a hydrophilically modified carbon-based material are used within the above ratio range, the viscosity of the binder is optimized so that the modified carbon-based material is uniformly dispersed and adheres to the substrate surface, enabling stable coating. In addition, it prevents rigidity of the coating layer caused by excessive use of the binder and maximizes the hydrophilicity of the modified carbon-based material to provide high wettability and moisture absorption. Consequently, the above ratio exhibits excellent effects in terms of physical stability, hydrophilicity, and hygroscopicity of the coating layer.

[0084] The paste composition of the present invention is characterized by comprising, based on 100 parts by weight of the total, 50 to 80 parts by weight of a polymer binder, 10 to 30 parts by weight of a hydrophilically modified carbon-based material, and 0.1 to 25 parts by weight of a dispersant, preferably 60 to 70 parts by weight of a polymer binder, 15 to 25 parts by weight of a hydrophilically modified carbon-based material, and 0.1 to 20 parts by weight of a dispersant.

[0085] When a polymer binder, a hydrophilically modified carbon-based material, and a dispersant are used within the above ratio range, the polymer binder is sufficiently included to maintain the physical stability of the coating layer, while the hydrophilicity of the modified carbon-based material is maximized to provide high wettability and moisture absorption, ensure uniformity of the coating layer, and the dispersant prevents particle aggregation, thereby improving adhesion to the substrate.

[0086] In addition, the method for preparing a paste composition according to the present invention may include a first step of preparing a hydrophilically modified carbon-based material; a second step of mixing a polymer binder with the hydrophilically modified carbon-based material; and a third step of adding a dispersant to the mixed carbon-based material and polymer binder.

[0087] The description of the paste composition, the hydrophilically modified carbon-based material, the polymer binder, and the dispersant in the present invention is as described above.

[0088] In the present invention, to uniformly mix materials or promote a specific reaction within a mixture in which a polymer binder is mixed with a hydrophilically modified carbon-based material, the mixture is mechanically stirred or moved, and methods such as mechanical stirring, magnetic stirring, or ultrasonic stirring may be used.

[0089] More specifically, the mixing step is characterized by mixing by stirring at 500 rpm to 1000 rpm, preferably 600 rpm to 800 rpm for 10 to 60 minutes, preferably 20 to 40 minutes.

[0090] When stirring is performed at the stirring speed and time described above, the carbon-based material is uniformly dispersed without aggregation, thereby exhibiting consistent hydrophilicity and hygroscopicity within the coating layer. Furthermore, the appropriate stirring speed and time optimize the viscosity of the binder and the dispersion of the material, thereby improving the physical stability and performance of the coating composition. Consequently, the surface hydrophilicity and hygroscopicity of the coating layer are maximized, providing adhesion and durability to various substrates.

[0091] The coating composition of the present invention is characterized in that the mixing ratio of the paste and the polymer binder is 1:1 to 1:5, preferably 1:1 to 1:3, and more preferably 1:2.

[0092] When the paste and polymer binder are mixed within the above ratio range, the polymer binder and the hydrophilically modified carbon-based material are uniformly mixed, thereby optimizing the viscosity of the binder and ensuring that the modified carbon-based material adheres stably to the substrate surface. Through this, rigidity of the coating layer that may occur due to excessive use of binder is prevented, and high wettability and moisture absorption can be achieved by maximizing the hydrophilic properties of the modified carbon-based material.

[0093] In particular, a 1:2 mixing ratio provides the optimal effect in maximizing the physical stability, hydrophilicity, hygroscopicity, and spreadability of the coating layer. The coating layer formed with this ratio exhibits excellent physical strength while maintaining surface uniformity, allowing it to adhere strongly to various substrate surfaces. Consequently, the coating composition of the present invention can provide a stable coating layer with excellent hydrophilicity and hygroscopicity, as well as physical durability, thereby possessing technical advantages suitable for various industrial applications.

[0094] In addition, when the paste and polymer binder are mixed within the above ratio range, the polymer binder and the hydrophilically modified carbon-based material are uniformly mixed, thereby optimizing the viscosity of the binder and ensuring that the modified carbon-based material adheres stably to the substrate surface. Through this, rigidity of the coating layer that may occur due to excessive use of binder is prevented, and high wettability and moisture absorption can be achieved by maximizing the hydrophilic properties of the modified carbon-based material.

[0095] In another example, the present invention relates to a coating method comprising the steps of: applying the coating composition to a substrate surface; and forming a coating layer on the substrate surface.

[0096] The coating composition in the present invention is as described above.

[0097] The step of applying to the surface of a substrate of the present invention can be performed in various ways to ensure uniformity of the coating layer, and may apply spray coating, bar coating, roll coating, applicator coating, doctor blade, screen printing, inkjet printing, comma, gravure, microgravure, in-situ multi-layer method, etc., but is not limited thereto.

[0098] In addition, the coating method of the present invention may include a step of drying at 100°C to 300°C for 5 to 60 minutes, preferably, a step of drying at 150°C to 200°C for 5 to 15 minutes.

[0099] When coated using the application method, temperature, and time described above, the coating layer formed on the substrate surface exhibits excellent hydrophilicity, hygroscopicity, spreadability, and peel strength. Specifically, the coating layer exhibits strong adhesion to the substrate surface and displays excellent affinity for water, allowing water droplets to spread and be absorbed quickly. Furthermore, the coating layer, treated under appropriate drying temperature and time conditions, maintains high durability and physical stability and can perform continuously without deformation or damage from the external environment.

[0100] In particular, the coating layer of the present invention maintains stable performance even in a humid environment and provides strong adhesion and high peel strength to various substrates. Thanks to these characteristics, the coating method of the present invention is highly suitable for industrial applications requiring hydrophilicity and durability, such as electronic devices, building materials, and energy storage devices.

[0101] In addition, the present invention relates to a method for preparing a coating composition comprising: a first step of preparing a paste; a second step of mixing a polymer binder into the paste; and a third step of adding a hydrophilically modified carbon-based material to the mixed paste and polymer binder.

[0102] In addition, the present invention relates to a method for preparing a coating composition, further comprising a fourth step of adding a carbon-based material.

[0103] In the present invention, the paste, polymer binder, hydrophilically modified carbon-based material, and coating composition are as described above.

[0104] Meanwhile, in the present invention, when using a carbon-based material such as graphene, it may be applied to a heat dissipation component or heat dissipation material such as a vapor chamber or wick as needed.

[0105] A vapor chamber is constructed by creating a vacuum in a thin metal box with a specially machined interior, filling it with a small amount of refrigerant, and sealing it. The refrigerant (typically water) is selected based on the temperature to be used, and a metal (typically copper or aluminum) with good thermal conductivity that does not react with the refrigerant is used as the material for the box. Unlike conventional heat pipes, a vapor chamber allows a single chamber to come into contact with an entire wide heat source. Because the interior of the chamber is a single continuous space, the usable wall structure and central area for the refrigerant's movement are extremely large, resulting in much higher heat transfer efficiency. Furthermore, even with a very thin film thickness—ranging from as thin as 0.02 mm to a maximum of 5 to 6 mm—it possesses heat dissipation performance that far surpasses that of multiple heat pipes of the same volume, allowing for simultaneous reduction in volume and weight. Consequently, when applied as a heat sink, a vapor chamber can reduce the conduction loss (Delta-T) by up to 50% compared to heat pipes, making it highly useful for various applications.

[0106] In the case of a wick, when a heat pipe is applied as a heat dissipation component, it creates a capillary effect to maintain cooling performance even when the heat pipe is inverted. It is applied either on the inner wall of the heat dissipation component or as a coating to enhance heat conduction and heat dissipation effects. In particular, the function is maintained well because the capillary force increases as the pore radius of the wick becomes smaller; however, since the heat transport capacity decreases when the pore radius of the wick is very small, it is important to form it appropriately.

[0107]

[0108] The present invention will be explained in more detail below through specific manufacturing examples and embodiments. However, these manufacturing examples and embodiments are intended to illustrate the invention and the scope of the invention is not limited to these manufacturing examples and embodiments.

[0109]

[0110] Preparation Example 1. Paste preparation

[0111] As shown in [Table 1] below, paste samples containing hydrophilically modified non-oxidized graphene were prepared using the conditions of each example and comparative example.

[0112] Classification (Unit: parts by weight) Preliminary Comparative Example 1 1 2 3 4 5 Epoxy binder 6 5 5 0 6 0 7 0 7 5 8 0 Hydrophilically modified non-oxidized graphene 2 3 0 2 5 2 0 1 5 1 0 Dispersant 1 5 2 0 1 5 1 0 1 0 1 0

[0113]

[0114] More specifically, hydrophilically modified non-oxidized graphene powder with a particle size of 5 μm and an epoxy binder were mixed in weight ratios. The mixing was performed by stirring at a speed of 700 rpm for 30 minutes using a paste mixer. After mixing was completed, 10 to 20 parts by weight of a dispersant were subsequently added according to each example and comparative example, based on 100 parts by weight of the mixture. The final paste was prepared by further stirring at 300 rpm for 20 minutes to ensure that the subsequently added dispersant was uniformly dispersed.

[0115] The paste prepared as described above was stabilized by removing impurities through washing and vacuum filtration steps and drying. Finally, the prepared paste samples were coated onto various substrate surfaces, and the hydrophilicity, hygroscopicity, and physical stability of the coating layer according to each example and comparative example were evaluated.

[0116]

[0117] Preparation Example 2. Preparation of a coating solution by adding an epoxy binder to a paste

[0118] As shown in [Table 2] below, a coating solution sample containing the paste of Example 1 was prepared using the conditions of each example and comparative example.

[0119] Classification (Unit: parts by weight) Preliminary Comparative Example 2678910 Paste composition of Example 1 33.32030406050 Epoxy binder 66.78070604050

[0120]

[0121] More specifically, a coating solution was prepared by mixing the paste of Example 1 and an epoxy binder in weight ratios.

[0122] The finally prepared coating solution samples were coated onto various substrate surfaces according to weight ratios, and the hydrophilicity, hygroscopicity, and physical stability of the coating layer according to each example and comparative example were evaluated.

[0123]

[0124] Preparation Example 3. Preparation of a coating solution by additionally adding hydrophilically modified non-oxidized graphene to the coating solution of Example 2.

[0125] As shown in [Table 3] below, a coating solution sample was prepared by additionally adding hydrophilically modified non-oxidized graphene to the coating solution of Example 2 using the conditions of each example and comparative example.

[0126] Classification (Unit: parts by weight) Example Preliminary Comparative Example 3 1 1 1 2 1 3 1 4 1 5 Coating composition of Example 2 9 5 9 9 9 7 9 3 9 1 8 9 Hydrophilically modified non-oxidized graphene 5 1 3 7 9 1 1

[0127]

[0128] More specifically, a coating solution was prepared by mixing hydrophilically modified non-oxidized graphene into the coating solution of Example 2 in weight ratios.

[0129] The finally prepared coating solution samples were coated onto various substrate surfaces according to weight ratios, and the hydrophilicity, hygroscopicity, and physical stability of the coating layer according to each example and comparative example were evaluated.

[0130]

[0131] Experimental Example 1. Comparative observation of Manufacturing Examples 1 to 3 by weight ratio

[0132] The pastes of each example and comparative example prepared according to Manufacturing Example 1 were coated onto a SUS substrate, and comparative observation experiments were performed on the contact angle, hygroscopicity, and physical stability. When a water droplet was dropped onto the surface of the coated substrate and the initial (0 seconds) and subsequent (3 seconds) contact angles were measured, in the case of Example 1, the initial contact angle was 58 degrees and the subsequent contact angle was 0 degrees, confirming that the water droplet was rapidly absorbed into the paste. On the other hand, in the case of Comparative Examples 1 to 5, the initial contact angle was measured in the range of 60 to 80 degrees, and the subsequent contact angle was also measured in the range of 15 to 40 degrees, indicating relatively low hydrophilicity and hygroscopicity.

[0133] In the physical stability evaluation, the peel strength of Example 1 was measured as 5B, showing superior results compared to the peel strengths of 4B or 3B of Comparative Examples 1 to 5. These results demonstrate that the paste according to Example 1 of the present invention imparts excellent hydrophilicity, hygroscopicity, and physical stability to the substrate surface, and additional experiments were conducted based on Example 1 below (see Table 4 below).

[0134] Classification Preliminary Comparative Example 11 23 45 Surface contact angle evaluation Initial (0s) 58 60 62 7 27 88 1 Later (3s) 06 9 28 3 5 40 Physical stability evaluation 5 B 4 B 4 B 4 B 3 B

[0135]

[0136] In addition, the coating compositions of each example and comparative example prepared according to Manufacturing Example 2 were coated onto a SUS substrate, and comparative observation experiments were performed on the contact angle, hygroscopicity, and physical stability.

[0137] As a result of measuring the initial (0 seconds) and later (3 seconds) contact angles by dropping a water droplet onto the surface of the coated substrate, in the case of Example 2, the initial contact angle was 48 to 50 degrees and the later contact angle was 13 to 15 degrees, confirming that the water droplet was rapidly absorbed into the paste. On the other hand, in the case of Comparative Examples 6 to 10, the initial contact angle was measured in the range of 50 to 70 degrees, and the later contact angle was also 20 to 30 degrees, showing relatively low hydrophilicity and hygroscopicity (see Table 5 below).

[0138] In particular, when less epoxy binder was added than in Example 2, it was not suitable for thin coating of 50 μm or less due to high viscosity. These results confirmed that the coating solution according to Example 2 of the present invention provides excellent hydrophilicity, hygroscopicity, and physical stability to the substrate surface while also being suitable for thin coating, and further experiments were conducted based on Example 2 below.

[0139] Classification Preliminary Comparative Example 2678910 Surface Contact Angle Evaluation Initial (0s) 486860545150 Later (3s) 132722191815

[0140]

[0141] In addition, the coating solutions of each example and comparative example prepared according to Manufacturing Example 3 were coated onto a SUS substrate, and comparative observation experiments were performed on the contact angle, hygroscopicity, and physical stability.

[0142] As a result of measuring the initial (0 seconds) and later (3 seconds) contact angles by dropping a water droplet onto the surface of the coated substrate, in the case of Example 3, the initial contact angle was 51 to 53 degrees and the later contact angle was 9 degrees, confirming that the water droplet was rapidly absorbed into the paste. On the other hand, in the case of Comparative Examples 11 to 15, the initial contact angle was measured in the range of 55 to 65 degrees, and the later contact angle was also 15 to 20 degrees, showing relatively low hydrophilicity and hygroscopicity (see Table 6 below).

[0143] In addition, when hydrophilically modified non-oxidized graphene was added in greater quantities than in Example 3, the contact angle and hygroscopicity were similar, but due to high viscosity, it was not suitable for thin coatings of 50 μm or less. These results confirmed that the coating solution substrate surface according to Example 3 of the present invention provides excellent hydrophilicity, hygroscopicity, and physical stability, while also being suitable for thin coatings, and thus additional experiments were conducted based on Example 3 below.

[0144] Classification Preliminary Comparative Example 31112131415 Surface Contact Angle Evaluation Initial (0s) 515655535252 Later ((3s) 91512101110

[0145]

[0146] Experimental Example 2. Comparison and observation of contact angles of 600㎛ SUS substrates coated with paste and coating solution

[0147] The paste of Example 1 was coated onto a 600 μm thick SUS substrate, and a contact angle comparison observation experiment was performed. When a water droplet was dropped onto the surface of the coated substrate and the initial (0 seconds) and subsequent (3 seconds) contact angles were measured, the initial contact angle was 58 degrees and the subsequent contact angle was 0 degrees, confirming that the water droplet was absorbed into the paste. Compared to the initial (0 seconds) and subsequent (3 seconds) contact angles of 132 degrees each on a 600 μm SUS substrate without any treatment, it was confirmed that the substrate coated with the paste had significantly improved surface hydrophilicity and hygroscopicity (Fig. 2).

[0148] In addition, due to the high viscosity of the paste, it was difficult to control the coating thickness to 50 μm or less. To solve this, a coating solution (Example 2) was prepared by mixing the paste and an epoxy binder in a 1:2 ratio. The coating solution of Example 2 had a lower viscosity, making it possible to control the coating thickness to 50 μm or less. The contact angle of the coated substrate was measured as an initial contact angle of 50 degrees and a subsequent contact angle of 15 degrees at 20 μm to 30 μm, and an initial contact angle of 48 degrees and a subsequent contact angle of 13 degrees at 10 μm to 15 μm. Although the initial contact angle actually decreased compared to the paste of Example 1, the subsequent contact angle showed a tendency to increase slightly. However, since the subsequent contact angle was also maintained at 15 degrees or less, it was determined that excellent surface hydrophilicity and hygroscopicity were secured, and it was simultaneously confirmed that it is possible to control a thin coating thickness of 50 μm or less (Fig. 2).

[0149]

[0150] Experimental Example 3. Comparison and observation of contact angles of 60㎛ SUS substrates coated with paste and coating solution

[0151] The paste of Example 1 was coated onto a 60 μm thick SUS substrate, and a contact angle comparison observation experiment was performed. A water droplet was dropped onto the surface of the coated substrate, and the initial (0 seconds) and subsequent (3 seconds) contact angles were measured. As a result, the initial contact angle was 49 degrees and the subsequent contact angle was 0 degrees, confirming that the water droplet was absorbed into the paste (Fig. 3).

[0152] In addition, due to the high viscosity of the paste, it was difficult to control the coating thickness to 50 μm or less. To solve this, a coating solution (Example 2) was prepared by mixing the paste and an epoxy binder in a 1:2 ratio. The coating solution of Example 2 had a lower viscosity, making it possible to control the coating thickness to 50 μm or less. The contact angle of the coated substrate was measured as an initial contact angle of 50 degrees and a subsequent contact angle of 15 degrees at 20 μm to 30 μm, and an initial contact angle of 48 degrees and a subsequent contact angle of 13 degrees at 10 μm to 15 μm. Although the initial contact angle actually decreased compared to the paste of Example 1, the subsequent contact angle showed a tendency to increase slightly. However, since the subsequent contact angle was also maintained at 15 degrees or less, it was determined that excellent surface hydrophilicity and hygroscopicity were secured, and it was simultaneously confirmed that it is possible to control a thin coating thickness of 50 μm or less (Fig. 2).

[0153]

[0154] In addition, a coating solution (Example 3) was prepared by mixing hydrophilically modified non-oxidized graphene into the coating solution of Example 2, taking into account the high viscosity of the paste and surface hydrophilicity and hygroscopicity. The contact angle of the substrate coated with the coating solution of Example 3 was measured as an initial contact angle of 53 degrees and a final contact angle of 9 degrees at 20 μm to 30 μm, and an initial contact angle of 51 degrees and a final contact angle of 12 degrees at 10 μm to 15 μm. Although the initial contact angle was similar to that of the coating solution of Example 2, the final contact angle was measured to be 12 degrees or less, confirming that water droplets were rapidly absorbed into the substrate surface (Fig. 3).

[0155] As a result of this experiment, it was confirmed that the coating solution of the present invention (Examples 2 and 3) provides excellent surface hydrophilicity, hygroscopicity, and thin film coating capability even on thin substrates.

[0156]

[0157] Experimental Example 4. Comparison of Viscosities According to Composition of Paste and Coating Solution

[0158] The effect on coating characteristics was evaluated by comparing the change in viscosity according to the composition of the paste and coating liquid of the present invention. First, the paste exhibited a very high viscosity value of 100,000 cP or higher, and due to the high viscosity, there were limitations when coating the substrate surface with a thickness of 50 μm or less.

[0159] Accordingly, in the case of Example 2, in which a coating solution was prepared by adding an epoxy binder, the viscosity value decreased to 240 cP, making it easy to control the coating thickness, while Example 3, in which hydrophilically modified non-oxidized graphene was added, showed a tendency for the viscosity to increase slightly, reaching up to 320 cP. Although the viscosity increased somewhat due to the subsequent addition of modified non-oxidized graphene, it was confirmed that the increase in viscosity within this range did not affect the coating process.

[0160]

[0161] Experimental Example 5. Comparison of peel strength of coating films according to the composition of paste and coating solution

[0162] The paste of the present invention (Example 1) and the coating solution (Examples 2 and 3) were coated onto a 600 μm SUS substrate, and the peel strength of the coating film according to each composition was compared.

[0163] When a coating film with a thickness of 50㎛ to 60㎛ was formed using a paste, and when coating films with thicknesses of 10㎛ to 15㎛ and 20㎛ to 30㎛ were formed using the coating solutions of Examples 2 and 3, a peel strength of 5B was exhibited in both cases, confirming high adhesion between the coating film and the SUS substrate. This confirmed that excellent adhesion to the SUS substrate is maintained regardless of the coating film thickness.

[0164] In addition, the paste and the coating solutions of Examples 2 and 3 were coated onto a 600 μm SUS substrate, respectively, and the peel strength was compared according to the addition of an epoxy binder or hydrophilically modified non-oxidized graphene. As a result, all three conditions showed a peel strength of 5B, confirming high adhesion between the coating film and the substrate. This confirmed that changes in the content of the coating composition do not affect the peel strength.

[0165] Additionally, a peel strength of 5B was observed even when the coating solutions of Examples 2 and 3 were dried at 180°C for 30 minutes, and it was confirmed that increasing the drying time did not affect the adhesion of the coating film. Furthermore, when the peel strength was measured after storing the coating film prepared with the paste and the coating solution of Example 2 at room temperature for one week, it was confirmed that the peel strength maintained a peel strength of 5B under both conditions, thereby confirming that the surface characteristics of the coating film and the adhesion to the SUS substrate did not change with changes in time and humidity.

[0166]

[0167] Through the results of this experiment, it was confirmed that both the paste and diluted coating compositions maintain high peel strength and provide excellent adhesion between the coating film and the substrate.

[0168]

[0169] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0170] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the present invention.

Claims

1. Polymer binder; Hydrophilically modified carbon-based material; and In a paste composition containing a dispersant, A paste composition characterized by the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material being 10:1 to 2:

1.

2. In Paragraph 1, The above paste composition is, A paste composition characterized by comprising, based on 100 parts by weight of total, 50 to 80 parts by weight of a polymer binder, 10 to 30 parts by weight of a hydrophilically modified carbon-based material, and 0.1 to 25 parts by weight of a dispersant.

3. In Paragraph 1, The above-mentioned hydrophilically modified carbon-based material is, (a) A step of manufacturing a carbon-based material having a D50 of 4㎛ to 10㎛ when analyzed by a particle size analyzer by mechanically processing a carbon raw material; (b) a step of mixing the carbon-based material prepared above into a hydrophilic polymer solution; and (c) A paste composition prepared by a stirring step.

4. In Paragraph 3, A paste composition characterized in that the carbon raw material is one or more selected from the group consisting of graphite, graphene, graphene oxide, graphene reduction, non-oxidized graphene, graphene nanoplatelets, carbon black, and carbon nanotubes, or a mixture of one or more selected types.

5. In Paragraph 1, The above dispersant is, A paste composition characterized by comprising one or more selected from the group consisting of water-based dispersants, oil-based dispersants, amphiphilic dispersants, ionic surfactants, nonionic surfactants, additives, thickeners, and emulsifiers, or a mixture of one or more selected types.

6. Step 1 of manufacturing a hydrophilically modified carbon-based material; A second step of mixing a polymer binder into the hydrophilically modified carbon-based material; and A method for preparing a paste composition comprising: a third step of adding a dispersant to the above-mentioned mixed hydrophilically modified carbon-based material and polymer binder.

7. In Paragraph 6, A method for preparing a paste composition, characterized in that the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material is 10:1 to 2:

1.

8. In Paragraph 6, The first step of manufacturing the above hydrophilically modified carbon-based material is, (a) A step of manufacturing a carbon-based material having a D50 of 4㎛ to 10㎛ when analyzed by a particle size analyzer by mechanically processing a carbon raw material; (b) a step of mixing the above carbon-based material into a hydrophilic polymer solution; and (c) A method for preparing a paste composition comprising a stirring step.

9. In Paragraph 6, The second step of mixing a polymer binder with the hydrophilically modified carbon-based material is, A method for preparing a paste composition, wherein the mixture is mixed by stirring at 500 rpm to 1000 rpm for 10 to 60 minutes.

10. A first step of manufacturing the paste; and A second step of mixing a polymer binder, In a method for preparing a coating composition, A method for preparing a coating composition, characterized in that the mixing ratio of the paste and polymer binder is 1:1 to 1:

5.

11. In Paragraph 10, A method for preparing a coating composition, further comprising a third step of adding a carbon-based material to the above-mentioned mixed paste and polymer binder.

12. In Paragraph 10, The first step of manufacturing the above paste comprises: a step of manufacturing a hydrophilically modified carbon-based material; a step of mixing a polymer binder with the hydrophilically modified carbon-based material; and a step of adding a dispersant. The step of mixing a polymer binder with the hydrophilically modified carbon-based material is performed by stirring at 500 rpm to 1000 rpm for 10 to 60 minutes, wherein the mixing ratio of the polymer binder and the hydrophilically modified carbon-based material is 10:1 to 2:

1. The above carbon raw material is characterized by being one or more selected from the group consisting of graphite, graphene, graphene oxide, graphene reduction, non-oxidized graphene, graphene nanoplatelets, carbon black, and carbon nanotubes, or by mixing one or more selected types. A method for preparing a coating composition, characterized in that the above-mentioned dispersant is one or more selected from the group consisting of water-based dispersants, oil-based dispersants, amphiphilic dispersants, ionic surfactants, nonionic surfactants, additives, thickeners, and emulsifiers, or a mixture of one or more selected types.

13. A coating composition prepared by a method for preparing a coating composition according to any one of claims 10 to 12.

14. A step of applying a coating composition according to claim 13 to a substrate surface; and The method includes the step of forming a coating layer on the surface of the substrate; A coating method comprising additionally a step of drying at 100℃ to 300℃ for 5 to 60 minutes.

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