KR101218508B1 - Ceramic-carbon composites and its process - Google Patents

Abstract

PURPOSE: A ceramic-carbon composite with excellent thermal conductivity and electric insulation property, and a manufacturing method are provided to have various ranges of thermal conductivity and electrical insulation. CONSTITUTION: A ceramic-carbon composite with excellent thermal conductivity and electric insulation property comprises a carbon body(A), a functional group or a coupling agent(B), and ceramics(C). The carbon body has the size of 10 nanometers to 1,000 micrometers. The functional group or coupling agent is chemically combined or physically absorbed to the surface of the carbon body. The ceramic is combined and coated to the carbon body by using the functional group or coupling agent as a medium. A ceramics-carbon complex has the electric resistance of 10^1-10^18ohm/sq. A manufacturing method of the ceramics-carbon complex comprises the following steps: introducing the functional group or coupling agent to the surface of the carbon body having the size of 10 nanometers-1,000 micrometers by a chemical bond or the physical adsorption; and synthesizing and coating the ceramics on the carbon body surface in a sol-gel method. [Reference numerals] (a) Alumina x 10,000; (b) Magnesium oxide x 10,000; (c) Silica x10,000; (d) Zirconium oxide x 10,000; (e) Zinc oxide x 10,000

Description

Ceramic-carbon composites and its manufacturing method {Ceramic-carbon composites and its process}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon material used as a filler for a heat dissipating polymer composite material, and more particularly, to a ceramic-carbon composite in which a ceramic is coated on a carbon body to have both thermal conductivity and electrical insulation.

Along with the rapid performance improvement of electronic products such as portable devices, computers, and televisions, the amount of heat generated in electronic products has also increased significantly, so that effective heat dissipation materials are required. In the past, metals such as aluminum were used as heat dissipating materials. However, due to the industrial demand for light weight and cost reduction of electronic materials, it is being replaced with heat dissipating polymer composites. Is expected to continue rising.

The heat dissipating polymer composite material is largely divided into a material having electrical conductivity and a material having electrical insulation based on the electrical conductivity. Graphite is mainly used as a filler of the polymer composite material having electrical conductivity. Graphite is not only excellent in its thermal conductivity but also has a cost-effectiveness and ease of processing of raw materials. As a filler of the polymer composite material having electrical insulation, boron nitride is mainly used, and the boron nitride has good electrical insulation and excellent thermal conductivity.

Borne nitride is excellent in both thermal conductivity and electrical insulation, but there are some problems. First, borne nitride is about several to ten times more expensive than graphite, which greatly increases the cost of the product. Secondly, the larger the particle size of the thermally conductive filler is, the better the heat dissipation of the heat dissipating polymer composite is, and the production of the boron nitride (100 μm or more) having a large particle size is not commercially well performed. The larger the particle size of the filler, the better the heat dissipation is because the area and the number of interfacial thermal resistance between the filler and the polymer decrease. It is understood that none of the synthetic bournitrides commercially available is more than 30 μm in size.

Due to the above problems, the thermal conductivity (10 W / m K) of the electrically insulating heat dissipating polymer composite material currently commercialized is significantly lower than that of the electrically conductive heat dissipating polymer composite material (20 W / m K). .

An object of the present invention is to provide a ceramic-carbon composite that has excellent thermal conductivity and electrical insulation by coating a ceramic on a carbon body (graphite, etc.) having advantages such as excellent thermal conductivity, economic efficiency, and ease of processing. In the present invention, the carbon body to provide insulation by coating the ceramic is not limited to graphite, but includes all the carbon particles of various properties ranging from nanometers to hundreds of micrometers.

However, technical problems to be achieved by the present invention are not limited to the above-mentioned problems, and other technical problems will be clearly understood by those skilled in the art from the following description.

In the present invention,

The following carbon body (A) having a size in nanometers to several hundred micrometers; The following functional groups and coupling agents (B) chemically bonded to or physically adsorbed on the surface of the carbon body (A); The ceramic-carbon composite having the electrical resistance in the range of 10 ¹ to 10 ¹⁸ mW / sq comprises the following ceramics (C) bonded to and coated on the carbon body (A) via this functional group or coupling agent (B). Is provided.

A: Graphite, Expandable Graphite, Expanded Graphite, Graphene, Carbon Fiber, Carbon Nano Fiber and Carbon Nanotubes (CNTs) One or more carbon bodies selected from the group consisting of

B: at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a silane coupling agent, a zirconia coupling agent, a titanate coupling agent and a polymer having N-alkyl or N, N-dialkyl amide groups

C: at least one ceramic selected from the group consisting of magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), zinc oxide (ZnO), zirconium oxide (ZrO ₂ ), and silica (SiO ₂ )

In the present invention,

(a) introducing the following functional group or coupling agent (B) by chemical bonding or physical adsorption onto the surface of the following carbon body (A) having a size of nanometers to several hundred micrometers,

(b) synthesizing and coating the following ceramic (C) on the surface of the carbon body (A) by a sol-gel method by reacting a carbon precursor (A) into which a functional group or a coupling agent (B) is introduced and a ceramic precursor

Provided is a method of manufacturing a ceramic-carbon composite having an electrical resistance in the range of 10 ¹ to 10 ¹⁸ mA / sq.

In one embodiment of the present invention, the step of introducing the functional group or coupling agent (B), may be introduced into the hydroxyl group or carboxyl group on the surface of the carbon body (A) in an acidic solution of pH 6 or less. Alternatively, the coupling agent may be chemically bonded to the surface of the carbon body (A) or to a hydroxyl group or a carboxyl group previously introduced. The coupling agent may preferably be one or more selected from the group consisting of a silane coupling agent, a zirconia coupling agent and a titanate coupling agent.

In another embodiment of the present invention, the step of introducing the functional group or coupling agent (B), after dissolving the polymer having N-alkyl or N, N-dialkyl amide group in water or alcohol solution (A) ) And stirring to physically adsorb the polymer onto the carbon body (A).

Preferably, the step of synthetic coating the ceramic (C), the ceramic precursor in a solution of pH 1 ~ 6 or pH 7 or more containing the carbon body (A) and the catalyst introduced with the functional group or coupling agent (B). After mixing and mixing, the polymerization reaction is carried out to synthesize a ceramic (C) on the surface of the carbon body (A).

The present invention also provides a heat dissipating polymer composite material using the ceramic-carbon composite as a filler.

In the present invention, it is possible to obtain a ceramic-carbon composite by coating various kinds of ceramics on the surface of the carbon body of various shapes and sizes by the sol-gel method, by controlling the type and amount of the ceramics coated, the synthesis conditions of the ceramics, etc. Ceramic-carbon composites with thermal conductivity and electrical insulation can be produced. The ceramic-carbon composite of the present invention is economical due to low energy required for the manufacturing process and short process time, and has excellent thermal conductivity and electrical insulation at the same time, and thus can be widely used in various fields.

1 is a scanning electron microscope photograph of a 10,000-fold magnification of the surface of a ceramic-carbon composite prepared in an embodiment of the present invention, a) alumina / graphite composite (Example 2), b) magnesium oxide / graphite composite (Example 3), c) is a silica / graphite composite (Example 5), d) a zirconium oxide / graphite composite (Example 7), and e) a zinc oxide / graphite composite (Example 8).
2 is a schematic diagram of a method for producing a ceramic-carbon composite of the present invention.

The ceramic-carbon composite of the present invention comprises a carbon body, a functional group or coupling agent chemically bonded to or physically adsorbed on the surface thereof, and a ceramic coated on the carbon body via the functional group or coupling agent, It has an electrical resistance in the range of 10 ¹ to 10 ¹⁸ mA / SQ. The ceramic-carbon composite is obtained by introducing a functional group or a coupling agent through chemical bonding or physical adsorption on the surface of the carbon body and then reacting with a ceramic precursor to synthesize and coat the ceramic on the surface of the carbon body by the sol-gel method.

The carbon body may include graphite, expandable graphite, expanded graphite, graphene, carbon fiber, carbon nano fiber, and carbon nanotubes. One or more carbon bodies selected from the group consisting of CNTs), ranging in size from nanometers to hundreds of micrometers. In particular, the carbon body may be any one or a mixture of two or more of graphite, expandable graphite, and expanded graphite.

The functional group or coupling agent, preferably 1 selected from the group consisting of a hydroxyl group, a carboxyl group, a silane coupling agent, a zirconia coupling agent, a titanate coupling agent and a polymer having N-alkyl or N, N-dialkyl amide groups More than species. In the ceramic-carbon composite of the present invention, the carbon body and the ceramic are preferably chemically bonded or physically adsorbed through the functional group or the coupling agent.

The silane coupling agent (Silane Coupling Agent) is, for example, aminoethyl aminopropyl triethoxy silane, aminopropyl trimethoxy silane, aminopropyl triethoxy silane, aminoethyl aminopropyl methyl dimethoxy silane, phenyl tri One or more of ethoxy silane, tetraethyl ortho silicate, diethoxydimethyl silane, phenyl aminopropyl trimethoxy silane and aminoethyl aminopropyl trimethoxy silane may be used, but is not limited thereto. The titanate coupling agent (Titanate Coupling Agent) is, for example, isopropyl tri dioctylphosphate titanate, isopropyl trioleyl titanate, isopropyl tristyryl titanate, isopropyl tridode It may be one or more of silbenzenesulfonate titanate, isopropyl tridioctylpigophosphate titanate, tetraisopropyl didioctylphosphate titanate, but is not limited thereto. The zirconia coupling agent (Zirconate Coupling Agent) is, for example, zirconium IV, 2,2 bis-2-propenoletomethyl butenoleto trisdioctylpyrophosphato-o, zirconium 1,1 It may be one or more of bis-2-propenoletomethyl butanoleto tris 2-amino phenyleto, but is not limited thereto. The polymer having an N-alkyl, N, or N-dialkyl amide group is, for example, poly (N-acetylethylenimine), Poly (2-methyl-2-oxazoline), Poly (N, N-dimethylacrylamide), Poly (N -vinylpyrrolidone) may be one or more, but is not limited thereto.

The ceramic synthesized on the surface of the carbon body is one selected from the group consisting of magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), zinc oxide (ZnO), zirconium oxide (ZrO ₂ ), and silica (SiO ₂ ). The above is ceramic. The ceramic precursor may be at least one of magnesia precursor, alumina precursor, zinc oxide precursor, zirconia precursor, and silica precursor. The magnesia precursor may be, for example, one or more of magnesium nitrate (Mg (NO ₃ ) ₂ 6H ₂ O), magnesium acetate tetrahydrate, magnesium methoxide, and the like. It is not limited. The alumina precursor may be, for example, one or more of aluminum nitrate nonahydrate, aluminum isopropoxide, and aluminum sec-butoxide, but is not limited thereto. It is not. The zinc oxide precursor may be one or more of zinc nitrate and zinc acetate, but is not limited thereto. The zirconia precursor may be, for example, one or more of ZrO (NO 3) 2 H 2 O, Zr (NO 3) 2 x H 2 O, zirconium n-propoxide, but is not limited thereto. . Silica precursors include, for example, aminopropyltriethoxysilane (APTES), aminopropyltrimethoxysilane (APTMS), 3-mercaptopropyltriethoxysilane (MPTES), 3-mercaptopropyltrimethoxysilane (MPTMS), tetraethyl orthosilicate (TEOS), tetramethyl orthosilicate (TMOS) and tetrapropyl orthosilicate (TPOS). It may be one or more, but is not limited thereto.

Hereinafter, the manufacturing method of the ceramic-carbon composite of this invention is demonstrated. Description of each of the components constituting the ceramic-carbon composite is the same as above, and the overlapping description is omitted.

In the method for producing a ceramic-carbon composite of the present invention, (a) a step of introducing a functional group or a coupling agent on the surface of the carbon body, and (b) a carbon body by reacting the carbon precursor, into which the functional group or coupling agent is introduced, and the ceramic precursor are reacted. Synthesizing and coating ceramics on the surface. Figure 2 shows a schematic diagram of a method for producing a ceramic-carbon composite of the present invention. Hereinafter, each step will be described in detail.

Carbon  On the surface Coupling agent  Introduction stage

Since the surface of the carbon body is hydrophobic, it is difficult to properly disperse in an aqueous solution, and since there is no functional group, it is difficult to coat the ceramic as it is, and even though the ceramic is coated, pores are present on the surface, which has a fatal effect on thermal conductivity. Therefore, a surface modification step of introducing a functional group on the surface of the carbon body is required, and surface modification can be divided into modification through chemical bonding and modification through physical bonding.

Modification Through Chemical Bonding

Modification through chemical bonding introduces a hydroxyl group or a carboxyl group on the surface of the carbon body, or introduces a coupling agent. In one embodiment of the present invention, a hydroxyl group or a carboxyl group is introduced to the surface of the carbon body in an acidic solution of pH 6 or less. In still another embodiment of the present invention, a silane coupling agent (Silane Coupling Agent); Titanate coupling agents (Titanate Coupling Agent); At least one of zirconate coupling agents is introduced.

In detail, there are three major methods for chemically modifying the surface of a carbon body. The first is to introduce hydroxyl groups into the carbon body in hot acidic solutions. This method may destroy the structure of the carbon body, resulting in the loss of the excellent properties of the carbon body. The second method is to introduce a functional group using a phase transfer catalyst. When a carbon body dispersed in an organic solvent and an oxidizing agent dissolved in water are mixed, carbon is transferred through the ion transfer by the phase transfer catalyst at the interface between the two solutions. Nucleophilic substitution reactions occur on the surface of the body resulting in functional groups. A coupling agent is then introduced into the surface modified carbon body. The third method is to introduce a coupling agent by introducing a carbon body into an aqueous solution of weak acid. The coupling agent may be used either alone or in combination of two or more of the silane coupling agent, titanate coupling agent, and zirconate coupling agent. Preferably the second or third method is used.

Modification through physical coupling

The step of introducing the functional group into the physical bond of the coupling agent on the surface of the carbon body preferably uses a polymer having N-alkyl or N, N-dialkyl amide groups as the coupling agent. The hydrophobic part of the polymer chain covers the surface of the carbon body, and the hydrophilic part is directed out of the solution to form a network between the polymer chains, thereby strongly adsorbing physically. The polymer is preferably one or more selected from the group consisting of poly (N-acetylethylenimine), Poly (2-methyl-2-oxazoline), Poly (N, N-dimethylacrylamide) and Poly (N-vinylpyrrolidone) Each of these may be used alone or in combination of two or more thereof. At this time, it is preferable to use a polymer having a larger molecular weight as the carbon body has a larger size.

After dissolving a polymer having an N-alkyl or N, N-dialkyl amide group in water or an alcohol solution, the carbon body is added and stirred to physically adsorb the polymer to the carbon body. After the carbon is added to the solution, the mixture is stirred for at least 15 minutes. After the filtering and drying process, the coupling agent is physically adsorbed on the surface of the carbon body to obtain a carbon body in a state capable of hydrogen bonding. The alcohol may be, for example, one or a mixture of two or more of methanol, ethanol, propanol, butanol, acetone, toluene, dimethylformamide and xylene, but is not limited thereto.

By the sol-gel method Carbon  Synthesis of ceramic on the surface

The ceramic precursor is reacted with the surface-modified carbon body by the previous method to synthesize the ceramic on the surface of the carbon body by the sol-gel method. At this time, the shape, amount, uniformity and thickness of the ceramic coated on the surface of the carbon body can be controlled according to the conditions of the sol-gel synthesis method, the amount and the kind of the precursor, which affects the thermal conductivity and electrical insulation of the obtained ceramic-carbon composite. Ceramic-carbon composites with a wide range of thermal and electrical insulation can be produced.

The sol-gel process can be carried out by using a common method, the Stover method or by changing the conditions thereof. Preferably, the ceramic precursor is added and mixed in a solution of pH 1-6 or pH 7 or more including the surface-modified carbon body and the catalyst, followed by polymerization to synthesize the ceramic on the surface of the carbon body. Specifically, an acid catalyst or a basic catalyst having a ratio of water to an alcohol solvent is introduced under an atmosphere of nitrogen or argon at a temperature of 15 to 80 ° C., and the carbon alkoxides of the surface-modified carbon body and the ceramic precursor are solution. To be introduced. In one embodiment of the present invention, at a polymerization temperature of 15 ~ 80 ℃ at a pH 7 or more solution conditions of 5 minutes or more, preferably 5 minutes to about 3 hours, pH 1-6 solution conditions of 1 hour or more, preferably Stir for about 1 hour to 7 days to synthesize and coat a ceramic on the surface of the carbon body. In another embodiment of the present invention, by reacting at least 1 minute, preferably 5 minutes to 10 minutes at a polymerization temperature of 30 ~ 80 ℃ in a microwave oven to synthesize and coat the ceramic on the surface of the carbon body. Description of the ceramic and the ceramic precursor to be synthesized is the same as above.

As the catalyst, an acid solution or a basic solution is used. As the acidic catalyst, any one or more selected from the group consisting of acetic acid, potassium fluoride, hydrofloric acid, hydrochloric acid, sulfuric acid, and nitric acid is used as a mixed solution having a pH of 1 to 6. As the basic catalyst, any one selected from the group consisting of ammonium hydroxide, tetrapropyl ammonium chloride, tetrapropyl ammonium hydroxide, potassium hydroxide, tetrabutylammonium bromide, tetrabutylammonium chloride and tetrabutylammonium hydroxide Use one or more of the solution at a pH of 7 or higher. The alcohol solvent is used by mixing one or two or more selected from the group consisting of methanol, ethanol, propanol, butanol, acetone, toluene, dimethylformamide and xylene.

The ceramic-carbon composite obtained according to the present invention may be used as a base material in various fields requiring heat dissipation and insulation, and in particular, may be used as a filler of a heat dissipating polymer composite material having electrical insulation. As a method of manufacturing the heat dissipating polymer composite material using the ceramic-carbon composite of the present invention as a filler, a conventional method of manufacturing the heat dissipating polymer composite material using a known filler such as graphite or born nitride can be applied.

Hereinafter, the present invention will be described in more detail with reference to specific examples. However, these examples are only for illustrating the present invention in more detail, the scope of the present invention is not limited by these examples.

Example 1

0.5 g of Poly (N-vinylpyrrolidone) (hereinafter referred to as “PVP”) was dissolved in 100 g of ethanol at room temperature, 1 g of graphite was added thereto, stirred for 1 hour, and then filtered and dried to obtain a graphite surface treated with PVP. 0.8 g of graphite surface-treated with PVP was added to 90 g of ethanol, and an aqueous ammonia solution was added so as to have a pH of 11.1. After adding 0.8 g of aluminum sec butoxide at room temperature and nitrogen atmosphere, the mixture was stirred for 12 hours, and then subjected to filtering and drying to prepare an alumina-graphite composite.

Example 2

1 g of PVP was dissolved in 100 g of ethanol at room temperature, dissolved in 1 g of graphite, stirred for 1 hour, and then filtered and dried to obtain a surface treated graphite. 0.8 g of the surface-treated graphite was added to 90 g of ethanol, and an aqueous ammonia solution was added to pH 11.1. After adding 0.8 g of aluminum sec butoxide at room temperature and nitrogen atmosphere, the mixture was stirred for 12 hours, and then subjected to a filter process and a drying process to prepare an alumina-graphite composite. The surface of the prepared alumina-graphite composite was magnified 10,000 times with a scanning electron microscope, and the result is shown in FIG.

Example 3

1 g of PVP was dissolved in 100 g of ethanol at room temperature, 1 g of graphite was added thereto, stirred for 1 hour, and then filtered and dried to obtain surface treated graphite. 0.8 g of graphite surface-treated with PVP was added to 90 g of ethanol, and an aqueous ammonia solution was added to pH 11.1. Then, after adding 0.8g of magnesium nitrate at room temperature and nitrogen atmosphere and stirring for 12 hours, a magnesium oxide-graphite composite was prepared through a filter process and a drying process. The surface of the prepared magnesium oxide-graphite composite was magnified 10,000 times with a scanning electron microscope, and the result is shown in b) of FIG. 1.

Example 4

1 g of PVP was dissolved in 100 g of ethanol at room temperature, 1 g of graphite was added thereto, stirred for 1 hour, and then filtered and dried to obtain surface treated graphite. 0.8 g of graphite surface-treated with PVP was added to 90 g of ethanol, and an aqueous ammonia solution was added to pH 11.1. Thereafter, 0.16 g of magnesium nitrate was added at room temperature and in a nitrogen atmosphere, followed by stirring for 12 hours. A magnesium oxide-graphite composite was prepared through a filter process and a drying process.

Example 5

1 g of PVP was dissolved in 100 g of ethanol at room temperature, 1 g of graphite was added thereto, stirred for 1 hour, and then filtered and dried to obtain surface treated graphite. 0.8 g of graphite surface-treated with PVP was added to 90 g of ethanol, and an aqueous ammonia solution was added to pH 11.1. After adding 0.8 g of TEOS at room temperature and nitrogen atmosphere, the mixture was stirred for 12 hours, and then a silica-graphite composite was prepared through a filter process and a drying process. The surface of the prepared silica-graphite composite was magnified 10,000 times with a scanning electron microscope, and the result is shown in c) of FIG. 1.

Example 6

1 g of PVP was dissolved in 100 g of ethanol at room temperature, 1 g of graphite was added thereto, stirred for 1 hour, and then filtered and dried to obtain surface treated graphite. 0.8 g of graphite surface-treated with PVP was added to 90 g of ethanol and acetic acid was added to pH 4. After adding 0.8g of the precursor at room temperature and nitrogen atmosphere, and stirred for 72 hours to prepare a silica-graphite composite through a filter process and a drying process.

Example 7

1 g of PVP was dissolved in 100 g of ethanol at room temperature, 1 g of graphite was added thereto, stirred for 1 hour, and then filtered and dried to obtain surface treated graphite. 0.8 g of graphite surface-treated with PVP was added to 90 g of ethanol, and an aqueous ammonia solution was added to pH 11.1. Thereafter, 0.8 g of zirconium n-propoxide was added thereto at room temperature and in a nitrogen atmosphere, followed by stirring for 12 hours. A zirconium oxide-graphite composite was prepared through a filter process and a drying process. The surface of the prepared zirconium oxide-graphite composite was magnified 10,000 times with a scanning electron microscope, and the result is shown in FIG.

Example 8

1 g of PVP was dissolved in 100 g of ethanol at room temperature, and then 1 g of graphite was added thereto, stirred for 1 hour, and then filtered and dried to obtain surface treated graphite. 0.8 g of graphite surface-treated with PVP was added to 90 g of ethanol, and an aqueous ammonia solution was added to pH 11.1. After adding 0.8 g of zinc nitrate at room temperature and nitrogen atmosphere, the mixture was stirred for 12 hours, and then a zinc oxide-graphite composite was prepared through a filter process and a drying process. The surface of the prepared zinc oxide-graphite composite was magnified 10,000 times with a scanning electron microscope, and the result is shown in FIG.

Example 9

2 g of acetic acid solution, 0.3 g of potassium permanganate, and 1 g of graphite were added to 100 g of water at room temperature, and 1 g of tetrabutylammonium bromide, which was a phase transfer catalyst, was added to the mixed solution and stirred for 24 hours to introduce hydroxyl groups to the graphite surface. Thereafter, 0.8 g of the hydroxyl group-introduced graphite obtained through the filter process and the drying process was added to 80 g of toluene added with 1.0 g of aminopropyl trimethoxy silane, dispersed in an ultrasonic cleaner for about 5 minutes, and then heated at 80 ° C. for about 2 hours. The reaction was carried out while stirring to introduce a silane coupling agent. 0.8 g of graphite into which the silane coupling agent was introduced was placed in 90 g of ethanol, and hydrochloric acid was added to pH 4. After adding 0.8 g of aluminum sec butoxide at room temperature and nitrogen atmosphere, the mixture was stirred for 12 hours, and then subjected to a filter process and a drying process to prepare an alumina-graphite composite.

Comparative Example 1

Graphite without surface treatment.

Comparative Example 2

After PVP 1g was dissolved in 100g of ethanol at room temperature, 1g of graphite was added thereto, stirred for 1 hour, and then a PVP-graphite composite was prepared through a filter process and a drying process.

[Property evaluation]

The electrical resistance of the ceramic-graphite composites prepared in Examples and Comparative Examples was measured according to ASTM D 257. Measurement results of the electrical resistance together with the composition of the ceramic-graphite composite are shown in Table 1 below.

In Table 1, the amount of PVP is a weight percentage of ethanol used in the step of modifying the surface of the graphite with PVP, and the amount of precursor is a weight percentage of the precursor to graphite added during sol-gel synthesis.

As shown in Table 1, when comparing the sheet resistance values of Examples 1 to 8 and Comparative Examples 1 and 2, it can be seen that the sheet resistance of the ceramic-graphite composite of the present invention is greatly increased by coating the ceramic.

Comparing Examples 3 and 4, it can be seen that the sheet resistance of the ceramic-carbon composite increases as the amount of the precursor added during sol gel synthesis increases.

Comparing Examples 5 and 6, when the pH is 11.1, the sheet resistance value is higher than when 4. This is a phenomenon in which a higher amount of ceramic is coated on the surface of graphite as the pH is increased during synthesis by the sol-gel method.

The present invention may be manufactured in various forms without being limited to the above embodiments, and those skilled in the art may implement the present invention in other specific forms without changing the technical spirit or essential features of the present invention. I can understand that it can be. Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive.

Since the ceramic-carbon composite of the present invention has excellent thermal conductivity and electrical insulation at the same time, and has productivity and economy, it can be widely used in various fields requiring heat dissipation and insulation, and particularly can be widely used in the field of heat dissipating polymer composite materials. .

Claims (16)

The following carbon body (A) having a size of 10 nanometers to 1000 micrometers; The following functional groups and coupling agents (B) chemically bonded to or physically adsorbed on the surface of the carbon body (A); A ceramic-carbon composite comprising the following ceramics (C) bonded to and coated on the carbon body (A) via this functional group or coupling agent (B) and having an electrical resistance in the range of 10 ¹ to 10 ¹⁸ mA / sq.
A: Graphite, Expandable Graphite, Expanded Graphite, Graphene, Carbon Fiber, Carbon Nano Fiber and Carbon Nanotubes (CNTs) One or more carbon bodies selected from the group consisting of
B: at least one selected from the group consisting of hydroxyl groups, carboxyl groups, silane coupling agents, zirconia coupling agents, titanate coupling agents and polymers having N-alkyl or N, N-dialkylamide groups
C: at least one ceramic selected from the group consisting of magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), zinc oxide (ZnO), zirconium oxide (ZrO ₂ ), and silica (SiO ₂ ) The method of claim 1,
The polymers having N-alkyl or N, N-dialkylamide groups include poly (N-acetylethyleneimine), poly (2-methyl-2-oxazoline), poly (N, N-dimethylacrylamide) and poly Ceramic-carbon composite, characterized in that at least one member selected from the group consisting of (N-vinylpyrrolidone). The method of claim 1,
The said silane coupling agent is aminoethyl aminopropyl triethoxy silane, aminopropyl trimethoxy silane, aminopropyl triethoxy silane, aminoethyl aminopropyl methyl dimethoxy silane, phenyl triethoxy silane, tetraethyl ortho silicate , At least one selected from the group consisting of diethoxydimethyl silane, phenyl aminopropyl trimethoxy silane and aminoethyl aminopropyl trimethoxy silane,
The titanate coupling agent isopropyl tri dioctylphosphate titanate, isopropyl trioleyl titanate, isopropyl tristyryl titanate, isopropyl tri dodecylbenzenesulfonate titanate, iso At least one member selected from the group consisting of propyl tridioctylpigophosphate titanate and tetraisopropyl didioctylphosphate titanate,
The zirconia coupling agent is zirconium IV, 2,2 bis-2-propenoletomethyl butenoleto trisdioctylpyrophosphato-o, and zirconium 1,1 bis-2-propenoletomethyl Butanoleto tris ceramic-carbon composite, characterized in that at least one member selected from the group consisting of 2-amino phenyleto. (a) introducing the following functional group or coupling agent (B) by chemical bonding or physical adsorption onto the surface of the following carbon body (A) having a size of 10 nanometers to 1000 micrometers,
(b) synthesizing and coating the following ceramic (C) on the surface of the carbon body (A) by a sol-gel method by reacting a carbon precursor (A) into which a functional group or a coupling agent (B) is introduced and a ceramic precursor
Method for producing a ceramic-carbon composite having an electrical resistance in the range of 10 ¹ ~ 10 ¹⁸ Ω / sq.
A: Graphite, Expandable Graphite, Expanded Graphite, Graphene, Carbon Fiber, Carbon Nano Fiber and Carbon Nanotubes (CNTs) One or more carbon bodies selected from the group consisting of
B: at least one selected from the group consisting of hydroxyl groups, carboxyl groups, silane coupling agents, zirconia coupling agents, titanate coupling agents and polymers having N-alkyl or N, N-dialkylamide groups
C: at least one ceramic selected from the group consisting of magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), zinc oxide (ZnO), zirconium oxide (ZrO ₂ ), and silica (SiO ₂ ) 5. The method of claim 4,
The step of introducing the functional group or coupling agent (B), the method of producing a ceramic-carbon composite, characterized in that to introduce a hydroxyl group or a carboxyl group on the surface of the carbon body (A) in an acidic solution of pH 6 or less. 5. The method of claim 4,
The step of introducing the functional group or the coupling agent (B) may include a silane coupling agent on the surface of the carbon body (A) or a hydroxyl group or a carboxyl group introduced in advance; Zirconia coupling agents; A method for producing a ceramic-carbon composite, wherein at least one of the titanate coupling agents is chemically bonded. 5. The method of claim 4,
In the step of introducing the functional group or coupling agent (B), after dissolving a polymer having N-alkyl or N, N-dialkylamide group in water or alcohol solution, the carbon body (A) is added and stirred to form a carbon body ( Method for producing a ceramic-carbon composite, characterized in that the polymer is physically adsorbed to A). The method of claim 7, wherein
The polymer is selected from the group consisting of poly (N-acetylethyleneimine), poly (2-methyl-2-oxazoline), poly (N, N-dimethylacrylamide) and poly (N-vinylpyrrolidone) Method for producing a ceramic-carbon composite, characterized in that at least one. The method of claim 7, wherein
The alcohol is a method of producing a ceramic-carbon composite, characterized in that at least one selected from the group consisting of methanol, ethanol, propanol, butanol, acetone, toluene, dimethylformamide and xylene. 10. The method according to any one of claims 4 to 9,
Synthetic coating of the ceramic (C), after mixing the ceramic precursor in a solution of pH 1 ~ 6 or pH 7 containing the carbon body (A) and the catalyst introduced with the functional group or coupling agent (B) after mixing And a polymerization reaction to synthesize a ceramic (C) on the surface of the carbon body (A). The method of claim 10,
The ceramic precursor is at least one selected from the group consisting of the following magnesia precursor (ⓐ), alumina precursor (ⓑ), zinc oxide precursor (ⓒ), zirconia precursor (ⓓ) and silica precursor (ⓔ). A method of preparing a carbon composite.
Ⓐ: at least one magnesia precursor selected from the group consisting of magnesium nitrate (Mg (NO ₃ ) ₂ 6H ₂ O), magnesium acetate tetrahydrate and magnesium methoxide
Ⓑ: at least one alumina precursor selected from the group consisting of aluminum nitrate nonahydrate, aluminum isopropoxide and aluminum sec-butoxide
Ⓒ: zinc oxide precursor of one or more of zinc nitrate and zinc acetate
Ⓓ: one or more zirconia precursors selected from the group consisting of ZrO (NO 3) 2 H 2 O, Zr (NO 3) 2 x H 2 O and zirconium n-propoxide
Ⓔ: Group consisting of APpropyl (Aminopropyltriethoxysilane), APTMS (Aminopropyltrimethoxysilane), MPTES (3-mercaptopropyltriethoxysilane), MPTMS (3-mercaptopropyltrimethoxysilane), TEOS (Tetraethyl Orthosilicate), TMOS (Tetramethyl Orthosilicate) and TPOS (Tetrapropyl Orthosilicate) More than one type of silica precursor The method of claim 10,
The catalyst is one selected from the group consisting of ammonium hydroxide, tetrapropyl ammonium chloride, tetrapropyl ammonium hydroxide, potassium hydroxide, tetrabutylammonium bromide, tetrabutylammonium chloride and tetrabutylammonium hydroxide It is the above basic catalyst,
A method of producing a ceramic-carbon composite, comprising adding a ceramic precursor to a solution having a pH of 7 or more, and mixing and reacting. The method of claim 10,
The catalyst is at least one acidic catalyst selected from the group consisting of acetic acid, potassium fluoride, hydrofloric acid, hydrochloric acid, sulfuric acid and nitric acid,
A method for producing a ceramic-carbon composite, comprising adding a ceramic precursor to a solution having a pH of 1 to 6, and mixing and reacting. The method of claim 10,
The polymerization reaction is a method for producing a ceramic-carbon composite, characterized in that the carbon body (A) is coated with a ceramic (C) by reacting for at least 5 minutes at a polymerization temperature of 15 ~ 80 ℃. The method of claim 10,
The polymerization reaction is a method of producing a ceramic-carbon composite, characterized in that the reaction in the microwave oven for 1 minute or more at a polymerization temperature of 30 ~ 80 ℃ to coat the carbon body (A) with a ceramic (C). A heat dissipating polymer composite material comprising the ceramic-carbon composite of claim 1 as a filler.

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