KR20180118073A - Graphite composition, mater batch comprising the same and graphite composite material comprising the same - Google Patents

Abstract

The present invention provides a graphite composition. According to an embodiment of the present invention, the graphite composition comprises: a graphite compound wherein nanoparticles with a catecholamine layer on a surface thereof are fixed on graphite; and at least one among graphite flakes, spherical graphite, and expansion graphite. Accordingly, the graphite composition has high dispersability in a base material which is a different material to allow a composite material realized by the same to exhibit uniform heat radiation performance and prevent mechanical strength degradation at a specific position. Also, commercialization with a base material, which is a different material, is excellent to provide an excellent interface property with the base material to allow a realized composite material to exhibit improved heat radiation performance and mechanical strength. Moreover, during injection/extrusion molding by being combined with a base material, forming is very easy and forming into a complex shape is possible.

Description

[0001] The present invention relates to a graphite composition, a masterbatch comprising the same, and a graphite composition embodying the same,

The present invention relates to a graphite composition, and more particularly, to a graphite composition which is excellent in light weight and heat radiation performance, can be easily injected into various shapes, can realize a heat dissipation member having excellent mechanical strength and durability of an injection molded article, And a graphite composite material embodied therewith.

Heat accumulation in electronic components, lamps, transducer housings, and other unwanted heat generating devices can severely limit operating life and reduce operating efficiency. Metals, which are good thermal conductors, have traditionally been used for thermal management devices such as heat sinks and heat exchangers. However, there is a problem that the metal part is heavy in weight and high in production cost.

In recent years, a heat dissipating member made of a polymer resin capable of being injection molded or extruded has been proposed, and a lot of research is continuing due to advantages such as light weight and low cost due to the material characteristics of the polymer resin itself.

The heat dissipation member is provided with a heat dissipation pillar for exhibiting a desired heat dissipation property. However, the heat dissipation pillar is inevitably different from a polymeric resin having a low thermal conductivity on a material, and problems arise in compatibility between dissimilar materials. For example, ideally, it is advantageous in terms of heat dissipation performance that the heat dissipation filler is uniformly dispersed in the polymer resin, but in reality, the heat dissipation filler is more likely to be concentrated and distributed in a specific position of the polymer resin, There is a problem that the mechanical strength is remarkably lowered due to frequent cracking or cutting at a specific position where the heat dissipation pillars are densely packed. In addition, when the content of the heat-radiating filler in the heat-radiating member is excessively increased, the manufactured heat-radiating member has a significantly low mechanical strength and is difficult to be molded, thereby limiting the heat-radiating filler content that can be provided in the heat-

Accordingly, there is an urgent need to develop a heat-radiating filler composition capable of sufficiently exhibiting heat-radiating performance at a desired level while securing lightweight properties, having excellent mechanical strength and durability, and capable of realizing a radiating member having excellent ease of injection molding.

Japanese Patent Application Laid-Open No. 10-2016-0031103

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a graphite composition capable of exhibiting uniform heat dissipation performance, The purpose is to provide.

Further, since the present invention is excellent in compatibility with a base material of a different material, it has excellent interfacial characteristics with a base material and can exhibit improved heat dissipation performance and mechanical strength, and is easy to form even during molding through injection / extrusion It is another object of the present invention to provide a graphite composition which can be improved, and can be molded into a complicated shape.

It is a further object of the present invention to provide a masterbatch for the production of graphite composites which can easily produce composites through the graphite composition according to the invention.

Another object of the present invention is to provide a graphite composite material which exhibits excellent heat radiation performance, has excellent mechanical strength, is excellent in light weight, is excellent in economy, and is also realized in a complicated shape.

In order to solve the above problems, the present invention provides a graphite composite in which nanoparticles having a catecholamine layer on its surface are fixed on the graphite; And a graphite composition comprising at least one graphite flake, spherical graphite and expanding graphite.

According to one embodiment of the present invention, the graphite composite and the graphite may be provided at a weight ratio of 1: 1 to 25, more preferably 1:15.

In addition, the graphite composite may further include at least a polymer layer coated on the catecholamine layer.

In addition, the graphite composite may have an average particle size of 10 to 900 탆.

In addition, the graphite composite may have an average particle size of 50 to 600 탆.

The graphite flakes may have an average particle size of 10 to 1,000 占 퐉, the expanded graphite may have an average particle size of 50 to 1,000 占 퐉, and the spherical graphite may have an average particle size of 10 to 100 占 퐉.

Further, the graphite may be expanded graphite.

The graphite may include graphite flake and expanded graphite, and the expanded graphite and graphite flake may be contained in a weight ratio of 1: 1 to 20, more preferably 1: 1 to 13.

The present invention also provides a master batch for the production of a graphite composite comprising a graphite composition and a thermoplastic polymer according to the present invention.

According to an embodiment of the present invention, the graphite composition may be 20 to 80% by weight of the total weight of the master batch.

The thermoplastic polymer compound may be at least one selected from the group consisting of polyamide, polyester, polyketone, liquid crystal polymer, polyolefin, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyphenylene oxide (PPO) (PEI) and polyimide, or a mixture or copolymer of two or more kinds selected from the group consisting of polyethersulfone (PES), acrylonitrile-butadiene-styrene copolymer (ABS), polyetherimide .

The present invention also provides a graphite composite material comprising a polymer matrix molded with a thermoplastic polymer and a heat dissipation filler comprising the graphite composition according to the present invention dispersed in the polymer matrix.

According to an embodiment of the present invention, there is provided a method of manufacturing a semiconductor device, which comprises a carbon fiber, a glass fiber, a calcium carbonate, a magnesium carbonate, mica, talc, silicon carbide, kaolin, calcium sulfate, barium sulfate, silicon dioxide, ammonium hydroxide, , And the strength modifier may be included in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the graphite composition.

The impact modifier may further include one kind of impact modifier selected from the group consisting of thermoplastic polyurethane (TPU) and thermoplastic polyolefin (TPO), wherein the impact modifier may be included in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the graphite composition.

Further, it may further include at least one additive selected from the group consisting of the above-mentioned dispersants, antioxidants, work improvers, coupling agents, flame retardants, light stabilizers, heat stabilizers and UV absorbers.

In addition, a protective coating layer may be further provided on at least a part of the outer surface of the polymer matrix.

According to another aspect of the present invention, there is provided a thermoplastic resin composition comprising a polymer matrix formed by molding a thermoplastic polymer compound to form a core portion and a cover portion surrounding the core portion, a first heat dissipation filler including a graphite composition dispersed in the core portion, There is provided a graphite composite material comprising a dispersed pigment including an inside of a covering portion.

According to an embodiment of the present invention, the covering portion may further include a second heat dissipation filler.

The present invention also provides a heat-dissipating composite material comprising a graphite composite according to the present invention and a support member provided to form at least one interface with the polymer matrix of the graphite composite.

According to the present invention, since the graphite composition has a high dispersibility in a base material of a different material, the composite material thus realized exhibits a uniform heat radiation performance and can prevent a mechanical strength from lowering at a specific position. In addition, since the compatibility with a base material of a different material is excellent and the interface property with the base material is excellent, the implemented composite material can exhibit improved heat dissipation performance and mechanical strength. Furthermore, it is very easy to form during molding by injection / extrusion combined with a base material, and molding into a complicated shape is also possible. Accordingly, the composite material can be widely applied to a variety of technical fields requiring heat dissipation as it exhibits excellent heat dissipation performance, has excellent mechanical strength, is excellent in light weight, and is excellent in economy.

1 is a perspective view of a graphite composite according to an embodiment of the present invention. FIG. 1B is a sectional view taken along a line X-X 'in FIG. 1A,
Figures 2 through 5 are cross-sectional views of graphite composites according to various embodiments of the present invention, and
6A and 6B are cross-sectional views of a heat-dissipating composite according to an embodiment of the present invention, in which the positions of the support members are different.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

The graphite composition according to an embodiment of the present invention includes a graphite composite in which nanoparticles having a catecholamine layer on its surface are fixed on graphite, graphite of at least one of graphite flake, spherical graphite and expanded graphite.

First, the graphite composite will be described.

The graphite composite 101 includes nanoparticles 20 and a catecholamine layer 30 bonded to the surface of a graphite 10 as shown in Figs. 1A and 1B, and further includes a polymer layer 40 .

The graphite 10 may be of a kind known in the art as a layered superposition of a planar macromolecule in which a hexagonal ring of carbon atoms is infinitely connected in layers and specifically includes graphite, high crystalline graphite and graphite Or natural graphite or artificial graphite. When the graphite 10 is a natural graphite, for example, it may be an expanded graphite expanded graphite, and when the graphite composite produced through the graphite composite is used in combination with the graphite described later, it may be more advantageous to achieve the object of the present invention have. The artificial graphite may be one produced by a known method. For example, a thermosetting resin such as polyimide is produced in a film shape of 25 μm or less and then graphitized at a high temperature of 2500 ° C. or higher to produce a monocrystalline graphite, or a hydrocarbon such as methane is pyrolyzed at a high temperature, ) To produce a highly oriented graphite.

The shape of the graphite 10 may be a known shape such as a spherical shape, a plate shape or a needle shape, or an irregular shape, for example, a plate shape.

In addition, the average particle size of the graphite 10 may be 10 to 900 탆, more preferably 30 to 500 탆, and may be 300 탆, for example. If the average particle diameter of the graphite 10 is less than 10 탆, the pore of the filtration filter may be closed during the washing process of the catecholamine component during the manufacturing process of the graphite composite 101, thereby making the dehydration process difficult.

Also, the graphite 10 may be a high purity graphite having a purity of 99% or more, which may be advantageous for exhibiting improved physical properties.

Next, the nanoparticles 20 bonded to the surface of the graphite 10 described above function as a medium capable of providing the graphite 10 with a catecholamine layer 30 to be described later. In detail, since the functional group capable of mediating a chemical reaction is hardly provided on the surface of the graphite 10, the catecholamine layer (hereinafter referred to as " catecholamine ") capable of improving the dispersibility in the different materials of the graphite 10 30) is not easily provided on the surface of the graphite 10, even when the catecholamine is treated with graphite, the amount of the catecholamine remaining in the graphite is very small. Further, in order to solve this problem, there is a limit to increase the amount of catecholamine present on the surface of the modified graphite even if the modification treatment is carried out so as to have a functional group on the surface of the graphite. However, in the case of graphite having nanoparticles on its surface, there is an advantage that catecholamines can be introduced into the graphite by the desired amount as they are easily bonded onto the surface of the nanoparticles.

In addition, in the graphite composite material or the heat-radiating composite material using the graphite composition, the nanoparticles 20 of the graphite composite 101 can function as an anchor. That is, when nanoparticles are not provided, there is an excited portion due to lack of compatibility at the interface formed between the graphite outer surface and the polymer matrix and / or the support member, or there is a problem such as lifting of the interface due to vibration, impact, There is a concern that peeling may easily occur.

However, among the nanoparticles 20 provided in the graphite composite 101, the nanoparticles in contact with the supporting member function as an anchors at the interface between the graphite 10 and the supporting member, and the nanoparticles in contact with the polymer matrix are graphite 10 and polymer By functioning as an anchor at the interface between the matrix, it is possible to prevent the polymer matrix from being separated from the supporting member. Lifting of the interface between the polymer matrix and the graphite composite 101 can also be prevented because the nanoparticles 20 of the graphite composite 101 serve as anchors to the polymer matrix.

The nanoparticles 20 may be a metal or a non-metal material that is solid at room temperature, and examples thereof include alkali metals, alkaline earth metals, lanthanides, actinides, transition metals, Semi-metals and the like. For example, the nanoparticles may be Ni, Si, Ti, Cr, Mn, Fe, Co, Cu, Sn, In, Pt, Au, Mg and combinations thereof.

The nanoparticles 20 may have an average particle diameter of 5 to 100 nm, more preferably 5 to 65 nm, and more preferably 10 to 50 nm, thereby performing functions as an anchor Can be suitable. If the average particle diameter of the nanoparticles is less than 5 nm, the function as an anchor for enhancing the interfacial bonding property between the support member and the polymer matrix may be insignificant. In addition, if the average particle diameter of the nanoparticles exceeds 100 nm, the number of nanoparticles formed on the graphite surface of a limited area may be reduced, and it may be difficult to exhibit the interface bonding properties to a desired level. Further, it is difficult to produce particles that are bonded onto the graphite, and there is a fear that they are produced as a single nano powder. Further, even when formed on graphite, it is difficult to be realized in the form of particles in accordance with covering the outer surface of the graphite wider, and as a result, the function as an anchor may be deteriorated. Further, as described later, when the catecholamine layer is introduced, as the amount of the catecholamine layer loaded in the graphite composite increases, the aggregation of the graphite composite becomes worsened and the dispersibility of the graphite composite in the polymer matrix decreases, And the durability of the aggregated portion of the graphite composite may be significantly reduced.

In addition, the nanoparticles 20 may preferably be in a crystallized state, occupying an area of 10% or more, more preferably 10 to 70% of the total surface area of the individual graphite 10. The nanoparticles 20 may be present in an amount of 3 to 50% by weight, more preferably 3 to 20% by weight based on the total weight of the graphite composite 101.

Next, the catecholamine layer 30 may be provided on at least the surface of the nanoparticles 20 described above. Through this, the catecholamine layer 30 can be formed on the surface of the nanoparticles 20, and the flowability, dispersibility, The interface coupling property can be improved. In addition, the catecholamine layer 30 itself has a reducing power, and amine functional groups in the catechol functional groups of the layer surface form covalent bonds by the Michael addition reaction. Thus, the catecholamine layer 30 is subjected to secondary surface modification For example, as a bonding material capable of introducing the polymer layer 40 into the graphite in order to exhibit further improved dispersibility in the polymer compound.

The catecholamine forming the catecholamine layer 30 is an ortho-group of the benzene ring, a term having a hydroxy group (-OH) and having a variety of alkylamines in the para-group Non-limiting examples of various derivatives of such structures include but are not limited to dopamine, dopamine-quinone, epinephrine, alphamethyldopamine, norepinephrine, For example, alphamethyldopa, droxidopa, indolamine, serotonin or 5-hydroxydopamine, and the like. For example, the catecholamine layer 30 may be dopamine ) Layer. The dopamine is a monomolecular substance having a molecular weight of 153 (Da) having a catechol and an amine functional group. For example, a substance to be surface modified is added to an aqueous solution having basic pH (about pH 8.5) containing dopamine represented by the following formula And after a certain period of time, a polydopamine (pDA) coating layer may be formed on the surface of the material by oxidation of the catechol.

[Chemical Formula 1]

At least one of R ₁ , R ₂ , R ₃ , R ₄ and R ₅ in Formula 1 is a thiol, a primary amine, a secondary amine, a nitrile, an aldehyde Imidazole, azide, halide, polyhexamethylene dithiocarbonate, hydroxyl, carboxylic acid, carboxylic acid, and the like. ester) or carboxamide (carboxamide), and the remainder may be hydrogen.

The thickness of the catecholamine layer 30 may be 5 to 100 nm, but is not limited thereto.

The polymer layer 40 may be further coated on the catecholamine layer 30 and the compatibility with the polymer compound forming the composite material may be increased due to the polymer layer 40, Coupling characteristics can be implemented. The polymer layer 40 may be formed of a thermosetting polymer compound or a thermoplastic polymer compound, and the specific types of the thermosetting polymer compound and the thermoplastic polymer compound may be known ones. As a non-limiting example, the thermosetting polymer compound may be a compound selected from the group consisting of epoxy-based, urethane-based, ester-based and polyimide-based resins, or a mixture or copolymer of two or more thereof. The thermoplastic polymer compound may be at least one selected from the group consisting of polyamide, polyester, polyketone, liquid crystal polymer, polyolefin, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyphenylene oxide (PPO), polyether sulfone Polyetherimide (PEI) and polyimide, or a mixture or copolymer of two or more kinds thereof. Alternatively, the polymer layer may be a rubber elastomer including natural rubber and / or synthetic rubber, and the like.

When the polymer layer 40 is further provided, the polymer layer may have a thickness of 1 to 100 nm. The polymer layer 40 may be contained in an amount of 0.01 to 20% by weight based on the total weight of the graphite composite.

The above-described graphite composite 101 includes a step of preparing a graphite-nanoparticle conjugate in which nanoparticles are formed on a graphite surface; And forming a catecholamine layer on the graphite-nanoparticle conjugate. The method may further include forming the catecholine layer and further forming a polymer layer.

The step of preparing the graphite-nanoparticle conjugate having the nanoparticles formed on the surface of the graphite according to an embodiment of the present invention can be adopted without limitation as long as it is a known method of forming nanoparticles on the graphite surface. In this example, conventional gas phase synthesis techniques for producing metal nanopowders include inert gas condensation (IGC), chemical vapor condensation (CVC), metal salt spray-drying Can be employed. However, the inert gas condensation (IGC) process can produce very fine nano metal powders with high purity. However, it requires a large energy and has a very low production rate, which limits the industrial application, and chemical vapor condensation (CVC) The process may be somewhat improved in terms of energy or production rate compared to the inert gas condensation (IGC) process, but it may be uneconomical because the cost of the precursor, the raw material, is very high. In addition, the metal salt spray drying process is economical because it uses an inexpensive salt as a raw material, but contamination at the drying stage and agglomeration of the powder can not be avoided and toxic by-products are generated, which is disadvantageous from the environmental viewpoint.

Preferably, nanoparticles can be formed on the graphite through an atmospheric pressure high-frequency thermal plasma. Specifically, mixing the graphite and the nanoparticle-forming powder; Injecting a gas into the prepared mixture; Vaporizing the nanoparticle-forming material through a high-frequency thermal plasma; And crystallizing the vaporized nanoparticle-forming material on the graphite surface.

In the step of mixing the graphite and the nanoparticle-forming powder, the mixing ratio between the two materials may be designed differently according to the purpose. Preferably, in order to provide the nanoparticles at a high density, the nanoparticle- 3 to 100 parts by weight. At this time, mixing can be performed using a separate stirrer.

Next, the gas mixture can be injected into the mixed mixture, and the injected gas can be classified into a sheath gas, a central gas, a carrier gas and the like depending on its function. These gases include an inert gas such as argon, hydrogen, A gas obtained by mixing these gases may be used, and preferably argon gas may be used. The sheath gas is injected to prevent vaporized nanoparticles from adhering to the inner surface of the wall and also to protect the wall surface from ultrahigh plasma. Argon gas of 30 to 80 lpm (liters per minute) can be used. In addition, the central gas is a gas which is injected to generate a high-temperature thermal plasma, and argon gas of 30 to 70 lpm can be used. Further, the carrier gas serves to supply the mixture into the plasma reactor, and argon gas of 5 to 15 lpm can be used.

Next, the nanoparticle-forming material can be vaporized through a high-frequency thermal plasma. The thermal plasma is an ionization gas composed of electrons, ions, atoms and molecules generated from a plasma torch using DC arc or high frequency inductively coupled discharge, and is a high-speed jet having a very high temperature and high activity ranging from several thousands to several tens of thousands K . Accordingly, in order to smoothly generate high-temperature plasma, a power of 10 to 70 kW is supplied to the power supply of the plasma apparatus, an arc is formed by electric energy, and argon gas used as a thermal plasma generating gas is used to generate about 10,000 K ultra-high-temperature plasma is generated. As described above, the ultra-high temperature thermal plasma generated by using argon gas as a gas while maintaining a power of 10 to 70 kW is generated at a higher temperature than the thermal plasma generated by the heat treatment method or the combustion method. At this time, the present invention can appropriately modify and use a known high-frequency thermal plasma (RF) method, and a conventional thermal plasma processing apparatus may be used.

Next, a step of crystallizing the vaporized nanoparticle-forming material on the graphite surface can be performed. In order to crystallize the vaporized nanoparticle-forming material on the graphite surface, quenching gas may be used. At this time, the quenching gas may be condensed or quenched to crystallize while suppressing the growth of nanoparticles.

The step of forming a catecholamine layer on the graphite-nanoparticle binder prepared by the above-described method may be performed. Specifically, dipping the graphite-nanoparticle binder into a weakly basic dopamine aqueous solution may be performed. And forming a poly-dopamine layer on the surface of the graphite-nanoparticle conjugate.

First, the method for preparing the weakly basic dopamine aqueous solution is not particularly limited. However, the method of preparing the weak basic dopamine aqueous solution is not particularly limited, but a pH 8 to 14 basic tris buffer solution (10 mM, tris buffer solution), more preferably a basic pH 8.5 basic tris The dopamine concentration of the weakly basic dopamine aqueous solution may be 0.1 to 5 mg / ml, preferably 2 mg / ml, by dissolving dopamine in the buffer solution.

After the graphite-nanoparticle conjugate is dipped in the prepared weakly basic dopamine aqueous solution, dopamine is spontaneously polymerized under basic and oxidative conditions to form a catecholamine layer, which is a polydopamine layer, on the graphite-nanoparticle conjugate. At this time, a polydopamine layer can be formed by further providing an oxidizing agent, and oxygen gas in the air can be used as an oxidizing agent without an oxidizing agent, and the present invention is not particularly limited thereto.

At this time, the dipping time determines the thickness of the polypodamine layer. In the case of using a dopamine aqueous solution having a pH of 8 to 14 and a dopamine concentration of 0.1 to 5 mg / ml, it is preferable to form a catecholamine layer with a thickness of 5 to 100 nm It is preferable to dip for 0.5 to 24 hours. Pure plate-like graphite can hardly form a dopamine coating layer on the graphite surface through such a method, but the catecholamine layer can be formed on the nanoparticles due to the nanoparticles. However, the present invention is not limited to the dipping method. For example, a blade coating, a flow coating, a casting, a printing method, a transfer method, a brushing, A polymer layer may be further formed by a known method such as spraying.

On the other hand, in order to further provide a polymer layer on the graphite composite having the catecholamine layer formed thereon, a graphite composite in which a polymer layer is formed can be produced by mechanically mixing a graphite composite with a dissolution solution or a molten melt in which a desired polymer compound is dissolved.

Next, the graphite to be mixed with the above-described graphite composite 101 will be described.

The graphite functions to suppress the secondary agglomeration of the graphite composite 101 described above so that the graphite composite is more uniformly dispersed in the polymer compound and a lighter weight composite material is realized. The above-mentioned graphite composite has a catecholamine layer in order to improve the fluidity, dispersibility and interface bonding characteristics when it is mixed with the polymer compound. However, since the catecholamine layer may cause the secondary agglomeration of the graphite complexes, The dispersibility of the graphite composite in the composite material may be impaired. The graphite prevents secondary agglomeration between the graphite composites, thereby exhibiting uniform physical properties for each region of the composite material implemented thereby and preventing a decrease in mechanical strength due to agglomeration.

The graphite may be at least one of an expandable graphite flake, an expanded graphite, and a spherical graphite, and the graphite composite realized through the graphite composite may exhibit another effect or exhibit a higher physical property . The spherical graphite may be, for example, a spherical graphite flake obtained by polishing the graphite flake.

The graphite flakes and expanded graphite exhibit improved performance in heat radiation performance, especially in horizontal heat conduction, when mixed with the graphite composite, and they can exhibit excellent mechanical strength in the state of being dispersed in the polymer matrix. In addition, the spherical graphite can complement the vertical thermal conductivity of the graphite composite. The graphite has excellent thermal conductivity and electrical conductivity in the horizontal direction of the material itself, but the above properties are not good in the vertical direction. This is due to the fact that free charge can move in the horizontal direction, but not in the vertical direction. Therefore, the composite material including graphite in general has different horizontal thermal conductivity and vertical thermal conductivity, There is a disadvantage that the heat dissipation effect is weak. However, in the case of the spherical graphite, such disadvantages can be improved and the thermal conductivity in the vertical direction can be improved.

The graphite flakes may have an average particle size of 10 탆 to 1,000 탆, more preferably 50 탆 to 500 탆. The expanded graphite may have an average particle diameter of 50 to 1,000 占 퐉, more preferably 100 to 500 占 퐉. In addition, the spherical graphite may have an average particle diameter of 10 mu m to 100 mu m, and more preferably 20 mu m to 40 mu m. When the average particle size of the graphite for each type satisfies the above numerical range, it may be very advantageous to suppress the aggregation phenomenon of the graphite composite described above in addition to the improvement of the thermal conductivity. In addition, the problems of graphite desorption in pellets, graphite composites, and heat-radiating composites that occur as the particle size becomes very small can be suppressed. In addition, it is possible to prevent the graphite from lowering in flowability in a molten polymer compound generated when using the graphite exceeding the preferable upper limit of the particle diameter range for each type, and to prevent the surface quality from deteriorating in the graphite composite or the heat-radiating composite.

On the other hand, when the average particle size of the graphite is made smaller than the average particle size of the graphite composite 101, some graphite interconnection may occur. In this case, bi-modal interaction between the large particles and small particles is used, High-density filling in the matrix is possible, and the heat conduction characteristic can be further improved.

Further, the graphite including at least one of graphite flake, expanded graphite and spherical graphite is preferably used in a weight ratio of 1: 1 to 25, more preferably 1: 1 to 15, May be provided in a weight ratio of 1: 1 to 10: 1. If the graphite has a weight ratio of less than 1: 1 based on the weight of the graphite composite, the degree of improvement of the heat radiation performance due to the graphite is insignificant and it may be difficult to prevent aggregation of the graphite composite. In addition, since most of the heat-radiating filler must be provided as a graphite composite, there is a risk of cost increase, which may be undesirable for reducing the weight of the composite material to be realized. On the other hand, if the graphite is present in a ratio of 1:25 by weight or more based on the weight of the graphite composite, the heat dissipation property of the composite material may be deteriorated. In particular, So that the radiation characteristic and vertical heat conduction performance of conducted heat can be remarkably deteriorated. In addition, due to the deterioration of interfacial bonding properties between different materials, the spacing between the polymer matrix and the graphite, the interface between the polymer matrix and the support member may become more frequent and worsened.

According to an embodiment of the present invention, the graphite provided together with the graphite composite 101 may be expanded graphite, and the graphite composite 101 may be made of graphite such as tensile strength, flexural strength, flexural modulus, Mechanical strength and horizontal thermal conductivity can be achieved at a high level.

Further, according to an embodiment of the present invention, the graphite provided together with the graphite composite 101 may be graphite flake and expanded graphite. In this case, it may be very advantageous to achieve an elevated horizontal thermal conductivity in contrast to the case of having only one type of expanded graphite or graphite flake, in addition to excellent tensile strength. More preferably, the expanded graphite and the graphite flake may be contained in a weight ratio of 1: 1 to 20, more preferably 1: 1 to 13. If the amount of graphite flake is less than 1: 1 by weight based on the weight of the expanded graphite, the flowability may be lowered in a mixed state with the molten polymer compound to make injection molding difficult. It can be difficult. Further, if the graphite flake is provided in a ratio of more than 1:25 by weight based on the weight of the expanded graphite, it may be difficult to achieve the increased horizontal thermal conductivity. In addition, there is a fear of a decrease in mechanical strength such as tensile strength, flexural modulus, and impact strength.

The above graphite composites and graphite compositions comprising graphite are embodied in a master batch for the production of graphite composites together with a thermoplastic polymer.

The graphite composite and the graphite may be contained in an amount of 20 to 80 wt%, more preferably 30 to 70 wt%, based on the total weight of the master batch. If the graphite composite and the graphite are less than 20 wt%, the thermal conductivity The physical properties of the resin may be deteriorated. If it exceeds 80% by weight, it may be difficult to prepare a master batch, and cracks and cracks in the prepared master batch may be severe and storage stability may be poor. Also, the composite material implemented therewith may also have a significantly reduced mechanical strength.

The thermoplastic polymer compound may be a known thermoplastic polymer compound and may be a material forming a polymer matrix of a graphite composite material described later. The thermoplastic polymer compound may be at least one selected from the group consisting of polyamide, polyester, polyketone, liquid crystal polymer, polyolefin, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyphenylene oxide (PPO), polyether sulfone Acrylonitrile-butadiene-styrene copolymer (ABS), polyetherimide (PEI) and polyimide, or a mixture or copolymer of two or more kinds thereof.

For example, the polyamide may be a known polyamide-based compound such as nylon 6, nylon 66, nylon 11, nylon 610, nylon 12, nylon 46, nylon 9T (PA-9T), kiana and aramid.

For example, the polyester may be a known polyester compound such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), or polycarbonate.

For example, the polyolefin may be a known polyolefin compound such as polyethylene, polypropylene, polystyrene, polyisobutylene, ethylene vinyl alcohol, and the like.

The liquid crystal polymer may be used in a solution or a polymer exhibiting liquid crystallinity in a dissolved state without limitation, and may be of a known kind, and thus the present invention is not particularly limited thereto.

Meanwhile, the master batch for producing the graphite composite may further include other additives such as a strength improver, an impact modifier, an antioxidant, a heat stabilizer, a light stabilizer, a plasticizer, a dispersant, a work improvement agent, a coupling agent, a UV absorber, an antistatic agent, .

The strength improving agent may be used without limitation in the case of known components capable of improving the strength of the composite material between the heat dissipation filler including the graphite composite and the graphite and the polymer compound. Examples of the strength improving agent include carbon fibers, glass fibers, Calcium carbonate, magnesium carbonate, mica, talc, silicon carbide, kaolin, calcium sulfate, barium sulphate, silicon dioxide, ammonium hydroxide, and the like. , Magnesium hydroxide, and aluminum hydroxide may be included as the strength improver. The strength improver may be included in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the graphite composition, but is not limited thereto. For example, when the strength modifier is glass fiber, the length of the glass fiber may be 2 to 8 mm.

In addition, the impact modifier may be used without limitation in the case of a known component capable of improving the impact resistance by exhibiting flexibility and stress relaxation property of the composite material between the graphite composite / graphite and the polymer compound. For example, a thermoplastic polyurethane TPU), thermoplastic polyolefin (TPO), maleic acid grafted EPDM, elastic particles of a core / shell structure, and rubber-based resin as impact modifiers. The thermoplastic polyolefin is a material group similar to a rubber, and is a linear polyolefin block copolymer having a polyolefin block such as polypropylene or polyethylene and a rubbery block, or an ethylene-propylene-diene monomer (EPDM) And specific thermoplastic polyolefins can be used as known ones. Thus, the description of specific types of the present invention will be omitted. Further, since the thermoplastic polyurethane can be a known one, the description of the specific kind is omitted. The elastic particles of the core / shell structure can be obtained by using an allyl-based resin as the core, and a polymer having a functional group capable of reacting with the thermoplastic polymer compound so as to increase the compatibility with the thermoplastic polymer compound Resin.

The impact modifier may be included in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the total amount of the graphite composition, but is not limited thereto.

In addition, the antioxidant is provided to prevent the main chain of the thermoplastic polymer compound from being broken by inhibiting radical generation by heat and / or shear stress during extrusion and injection, and to prevent discoloration due to heat generated in secondary processing . The antioxidant may be any known antioxidant without limitation, including but not limited to tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis , 4-di-t-butylphenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite or the like; Alkylated monophenols or polyphenols; Alkylated reaction products of polyphenols with dienes such as tetrakis [methylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] methane, or else similar; The butylated reaction product of para-cresol or dicyclopentadiene; Alkylated hydroquinone; Hydroxide thiodiphenyl ether; Alkylidene-bisphenol; Benzyl compounds; Esters of monohydric or polyhydric alcohols with beta - (3,5-di-tert-butyl-4-hydroxyphenyl) -propionic acid; Esters of monohydric or polyhydric alcohols with beta - (5-tert-butyl-4-hydroxy-3-methylphenyl) -propionic acid; (3,5-di-tert-butyl-l-4-hydroxyphenyl) propionate, ditallowyl thiopropionate, ditridecyl thiopropionate, octadecyl 3- Esters of thioalkyl or thioaryl compounds such as pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate or the like; Amides of beta - (3,5-di-tert-butyl-4-hydroxyphenyl) -propionic acid, or the like, or mixtures thereof. The antioxidant may be present in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the thermoplastic polymer.

The heat stabilizers may be used without limitation in the case of known heat stabilizers, but as a non-limiting example, triphenyl phosphite, tris- (2,6-dimethylphenyl) phosphite, tris- (mixed mono- Organic phosphites such as tris- (mixed mono-and di-nonylphenyl) phosphate or the like; Dimethylbenzene phosphonate, or other similar phosphonates, trimethylphosphates, or other similar phosphates, or mixtures thereof. The heat stabilizer may be contained in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the thermoplastic polymer compound.

The light stabilizers may be used without limitation in the known light stabilizers. For example, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2- Benzotriazole and 2-hydroxy-4-n-octoxybenzophenone or the like, or mixtures thereof. The light stabilizer may be contained in an amount of 0.1 to 1.0 part by weight based on 100 parts by weight of the thermoplastic polymer compound.

The plasticizer may be selected from known plasticizers without limitation, but examples thereof include dioctyl-4,5-epoxy-hexahydrophthalate, tris- (octoxycarbonylethyl) isocyanurate, Phthalate esters such as tristearin, epoxidized soybean oil or the like, or mixtures thereof. The plasticizer may be contained in an amount of 0.5 to 3.0 parts by weight based on 100 parts by weight of the thermoplastic polymer compound.

The antistatic agent may be selected from known antistatic agents without limitation, including, but not limited to, glycerol monostearate, sodium stearyl sulfonate, sodium dodecylbenzene sulfonate, polyether block Amides, or mixtures thereof, including, for example, BASF from Irgastat under the trade designation Irgastat; Arkema of the trade name PEBAX; And from Sanyo Chemical industries of Pelestat under the trade designation < RTI ID = 0.0 > of Pelestat. ≪ / RTI > The antistatic agent may be contained in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of the thermoplastic polymer compound.

As the non-limiting examples of the working improving agent, there may be mentioned metal stearate, stearyl stearate, pentaerythritol tetrastearate, beeswax, montan wax, wax, paraffin wax, polyethylene wax or the like, or a mixture thereof. The working modifier may be included in an amount of 0.1 to 1.0 part by weight based on 100 parts by weight of the thermoplastic polymer compound.

In addition, the UV absorber can be any known UV absorber without limitation, including, but not limited to, hydroxybenzophenone; Hydroxybenzotriazole; Hydroxybenzotriazine; Cyanoacrylate; Oxanilides; Benzoxazinones; 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3, -tetramethylbutyl) -phenol; 2-hydroxy-4-n-octyloxybenzophenone; 2- [4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl] -5- (octyloxy) -phenol; 2,2 '- (1,4-phenylene) bis (4H-3,1-benzoxazin-4-one); Bis [[(2-cyano-3,3-biphenylacryloyl) oxy] -2,2-bis [ Methyl] propane; 2,2 '- (1,4-phenylene) bis (4H-3,1-benzoxazin-4-one); Bis [(2-cyano-3,3-diphenylacryloyl) oxy] -2,2-bis [ Methyl] propane; Nano-sized inorganic materials such as titanium oxide, cerium oxide and zinc oxide having a particle size of less than 100 nm; Or the like, or mixtures thereof. The UV absorber may be contained in an amount of 0.01 to 3.0 parts by weight based on 100 parts by weight of the thermoplastic polymer compound.

In addition, the above-mentioned dispersant can be used without limitation as long as it is a component known as a dispersing agent for a carbon-based heat-radiating filler. As a non-limiting example, a polyester dispersant, a polyphenylene ether dispersant, Polyolefin-based dispersant, polyetherimide-based dispersant, polyether sulfone-based dispersant, polyarylate-based dispersant, polyarylate-based dispersant, polyarylate-based dispersant, polyamide-based dispersant, polyamideimide- Phenylene sulfide-based dispersants, polyimide-based dispersants; Based dispersants, polyether ketone-based dispersants, polybenzoxazole-based dispersants, polyoxadiazole-based dispersants, polybenzothiazole-based dispersants, polybenzimidazole-based dispersants, polypyridine-based dispersants, polytriazole- Based dispersing agent, polysulfone-based dispersing agent, polyurea-based dispersing agent, polyurethane-based dispersing agent, or polyphosphazene-based dispersing agent, and the like, or a mixture or copolymer of two or more selected from these.

The dispersant may be included in an amount of 0.2 to 6.0 parts by weight based on 100 parts by weight of the graphite composition.

The coupling agent may be a known coupling agent without limitation, and examples thereof include silane coupling agents, amine coupling agents, maleic acid graft polypropylene (MAH-g-PP), and maleic acid And graft EPDM (MAH-g-EPDM) may be used in combination. The coupling agent may be contained in an amount of 0.01 to 8.0 parts by weight based on 100 parts by weight of the thermoplastic polymer compound.

The flame retardant may also include, for example, halogenated flame retardants, like terebromo bisphenol A oligomers such as BC58 and BC52, brominated polystyrene or poly (dibromo-styrene), brominated epoxy, Bis (pentabromobenzyl) ethane, Mg (OH) _2, and Al (OH) ₂ , ethylenebis (pentabromobenzyl) ethane, decabromodiphenylene oxide, pentabromopentyl acrylate monomer, pentabromobenzyl acrylate polymer, OH) ₃ , a phosphor-based FR system such as melamine cyanurate, red phosphorus, melamine polyphosphate, phosphate ester, metal phosphinate, ammonium polyphosphate, expandable graphite , Sodium or potassium perfluorobutane sulfate, sodium or potassium perfluorooctane sulfate, sodium or potassium di Phenyl sulfonesulfonate and sodium- or potassium-2,4,6-trichlorobenzoate and N- (p-tolylsulfonyl) -p-toluenesulfimide phthanium salt, N- (N'- Boron) sulfanyl imide potassium salt, or a mixture thereof, but is not limited thereto. The flame retardant may be contained in an amount of 30 parts by weight or less based on 100 parts by weight of the graphite composition.

The process for preparing the master batch including the above-described graphite composition, thermoplastic polymer compound, and other additives may be a conventional known method. For example, the prepared master batch may be in the form of pellets, The present invention will not be described in detail.

Next, a graphite composite according to an embodiment of the present invention will be described.

As shown in FIGS. 2 and 3, the graphite composites 1000 and 1000 'include a polymer matrix 200 formed of a thermoplastic polymer compound and graphite composites 101 and graphite 102 and 103 dispersed therein including the polymer matrix. And a protective coating layer 300 may be further formed on the outer surface of the polymer matrix 200. The protective coating layer 300 may be formed on the outer surface of the polymer matrix 200. [

The graphite composite 101 and the graphite 102 and 103 in the heat dissipation filler 100 are dispersed only in the polymer matrix 200 in FIG. 2 or 3, but they may be arranged to be exposed to the outer surface.

As shown in FIG. 2, the heat-dissipating filler 100 may include one type of graphite, for example, an expanded graphite 102. The graphite 102, 103 may be made of graphite flake, spherical graphite, or expanded graphite. can do. Alternatively, as shown in FIG. 3, the heat-radiating filler 100 may include two types of graphite, graphite flake 102 and spherical graphite 103, thereby simultaneously exhibiting improved vertical thermal conductivity and horizontal thermal conductivity Lt; / RTI > Alternatively, two types of graphite combinations can include expanded graphite and graphite flakes, thereby allowing the composite to exhibit excellent mechanical strength and enhanced horizontal thermal conductivity, as described above.

The heat dissipation filler including the graphite composite 101 and the graphite 102 or 103 is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, and still more preferably 30 to 70% by weight based on the total weight of the graphite composite material 1000. By weight. If the heat-radiating filler is less than 10% by weight, the desired heat radiation performance and shielding performance may not be exhibited. In addition, if it is contained in an amount exceeding 90% by weight, the mechanical strength of the composite material is significantly lowered, and the moldability such as injection is reduced, and it may be difficult to realize the composite material in a complicated shape.

The shape and size of the polymer matrix 200 are not limited. For example, the polymer matrix may be in the form of a plate.

The protective coating layer 300 protects the polymer matrix 200 from external physical and chemical stimuli and prevents the graphite composite 101 and graphite 102 and 103 provided in the polymer matrix 200 from desorbing. . In addition, when the protective coating layer 300 is formed of an insulating material, it is possible to provide the required insulation property to the heat dissipating member of the electronic device.

The protective coating layer 300 may be formed of a known thermosetting polymer compound or a thermoplastic polymer compound. The thermosetting polymer compound may be one kind of compound selected from the group consisting of epoxy type, urethane type, ester type and polyimide type resins, or a mixture or copolymer of two or more kinds. The thermoplastic polymer compound may be at least one selected from the group consisting of polyamides, polyesters, polyketones, liquid crystal polymers, polyolefins, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyphenylene oxide (PPO) ), A polyetherimide (PEI), and a polyimide, or a mixture or copolymer of two or more kinds, but is not limited thereto.

The protective coating layer 300 may have a thickness of 0.1 to 1000 탆, but the protective coating layer 300 may be modified according to the purpose.

Meanwhile, the protective coating layer 300 may further include a metal, carbon, and / or ceramic heat spreader in order to further enhance heat dissipation and to exhibit thermal radiation characteristics to the outside air. In addition, when insulating property is required at the same time, known insulating heat-radiating fillers such as aluminum oxide, boron nitride, talc, magnesium oxide, silicon carbide and the like can be provided. When the protective coating layer 300 is a heat-dissipating coating layer, the thickness may be 10 to 50 μm. If the protective coating layer 300 has a thickness of more than 50 μm, the radiation characteristic may be considerably deteriorated.

In addition, the protective coating layer 300 may include a pigment. The graphite composites 1000 and 1000 'may be implemented in a dark or black color as the graphite is included as a heat-radiating filler, and in this case, the color problem may be avoided in some applications. The protective coating layer 300 may further include a known pigment for expressing a desired color.

However, when the thickness of the protective coating layer 300 is small, it may be impossible to express the desired color even with the addition of the pigment.

4 and 5, the graphite composite material 2000, 2000 'has a core portion 211, 221 and a cover portion 212a / 212b, 222a, 222b surrounding the core portion 210, 220. The graphite composite material 2000, And a first heat dissipation pillar 100 'is provided in the deep portions 211 and 221 and a pigment 400 is formed on the covering portions 212a / 212b and 222a / 222b. To express any desired color different from the color of the deep portion.

The first heat-dissipating filler 100 'is the same as that of the heat-dissipating filler 100 described above.

The core portions 210 and 220 and the covering portions 212a / 212b and 222a / 222b may be formed by molding a thermoplastic polymer compound. For example, the core portions 210 and 220 and the covering portions 212a and 212b may be realized by dual injection. Specifically, the polymer matrix may be embodied by first injecting a core part in a predetermined shape and then injecting a cover part so as to surround the outer part of the manufactured core part. However, the present invention is not limited thereto, and a polymer matrix may be realized by co-injection of a core portion and a cover portion. At this time, the thermoplastic polymer compounds forming the core parts 210 and 220 and the covering parts 212a / 212b and 222a / 222b may be the same or different and may be modified according to the purpose.

The covering portions 212a / 212b and 222a / 222b may have a thickness of 300 mu m to 1 cm, preferably, 300 mu m to 1 cm in order to prevent the hues 210 and 220 from shining out, / Lightness and the kind of the material of the covering portion, the content of the contained pigment, and the like.

The content of the pigment 400 may vary depending on the color type and degree of color to be expressed, and thus the present invention is not limited thereto.

On the other hand, when the thicknesses of the covering portions 212a / 212b and 222a / 222b are increased, the radiation and radiation characteristics of the core portions 211 and 221 may be deteriorated. Therefore, the covering portions 212a / 212b and 222a / The second heat dissipation pillar 500 may further include a second heat dissipation pillar 500 to minimize deterioration of radiation characteristics. The second heat-radiating pillar 500 may be a known heat-radiating pillar. For example, the second heat-radiating pillar 500 may further include a known heat-radiating pillar of metal, carbon, and / or ceramic. In addition, when insulating property is required at the same time, known insulating heat-radiating fillers such as aluminum oxide, boron nitride, talc, magnesium oxide, silicon carbide and the like can be provided. In addition, the content of the second heat-radiating filler (500) can be appropriately changed in consideration of the content of the pigment, the thickness of the covering portion, the type of the main resin forming the covering portion, and the like in the covering portion. .

4, a protective coating layer 310 may further be provided to prevent the pigment 400, the heat-radiating pillar 500, and the like from being detached from the outer portions of the covering portions 212a / 212b and 222a / 222b. The protective coating layer 310 is the same as the protective coating layer 300 described above, and thus a detailed description thereof will be omitted.

Meanwhile, as shown in FIGS. 6A and 6B, the graphite composite material 3100 described above may be implemented with the heat-radiating composite materials 3000 and 3000 'together with the support member 3200.

The graphite composite 3100 can exhibit excellent heat dissipation properties and light weight, but its use may be limited if a high level of mechanical strength is required together in some applications. Accordingly, the heat dissipation characteristics and the mechanical strength can be achieved at the same time through the provision of the support members that can complement the mechanical strength.

The support member 3200 performs a function of exhibiting a predetermined heat radiation performance while improving the mechanical strength of the heat radiation composite materials 3000 and 3000 '. The support member 3200 is excellent in compatibility with the polymer matrix and is not easily separated from the interface between the polymer matrix 200 and the support member 3200, but has excellent mechanical strength at a thin thickness and can be injection- And at the same time, the material having a predetermined thermal conductivity can be used without limitation. As a non-limiting example, the support member may be a metal, and may be a metal selected from the group consisting of aluminum, magnesium, iron, titanium, and copper, or an alloy containing at least one metal .

In addition, the support member 3200 may have a thickness of preferably 0.5 to 90%, more preferably 3 to 50%, with respect to the total thickness of the heat-dissipating composite materials 3000 and 3000 '. If the thickness of the support member 3200 is less than 0.5% with respect to the total thickness of the heat-dissipating composite material, it is difficult to ensure the desired level of mechanical strength and heat radiation performance. In addition, if it exceeds 90%, it is difficult to exhibit a desired heat radiation performance, and the formability into a complicated shape may be deteriorated. However, the present invention is not limited thereto, and the thickness of the support member 3200 may be appropriately changed in consideration of the mechanical strength required for the heat-dissipating composite material.

Further, the support member 3200 may have a plate shape with a predetermined width, a plurality of wires or bars spaced apart from each other at predetermined intervals on the inner side of a frame member having a predetermined shape such as a square shape or a circular shape, Structure and a variety of structures in which they are mutually combined.

6A, the support member 3200 may be positioned inside the polymer matrix of the graphite composite material 3100 to form an interface with the polymer matrix on the entire surface, or the lower surface of the support member 3200 may be formed of the graphite composite material 3100, Of the polymer matrix.

The description of the graphite composite material 3100 including the heat-radiating filler 100 is the same as that described above, and therefore, the present invention is not described herein. However, the nanoparticles of the graphite composite provided in the heat-dissipating filler 100 can function as an anchor as described above, so that the bonding property between the interface between the polymer matrix and the support member and the interface between the graphite and the polymer matrix of the graphite composite can be remarkably improved .

In addition, a protective coating layer 3300 may be provided on all or a part of the outer surface of the graphite composite 3100 and the support member 3200 forming the interface with the graphite.

Since the protective coating layer 3300 may be a protective coating layer which may be further included on the outer surface of the graphite composite material, a detailed description of the present invention will be omitted.

The graphite composite material and the heat-dissipating composite material according to the present invention can be embodied as electric / electronic parts. The electric / electronic part may be a part of an electric or electronic device used in various industries such as a battery field, an automobile field, an illumination field, an aerospace field, a display field, etc. Particularly, . In addition, the graphite composite material or the heat-radiating composite material according to the present invention can be used as the heat-radiating housing, the heat-radiating support member, the heat radiation circuit board, and the heat sink. However, the fields in which the graphite composite material and the heat-radiating composite material are used and the specific application are not limited thereto.

The present invention will now be described more specifically with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

≪ Example 1 >

The mixing ratio of graphite, which is plate-like expanded graphite having an average particle size of 300 탆, and nickel powder was mixed at a weight ratio of 1:19 for 10 minutes to prepare a raw material powder. Further, argon gas of 30 lpm and 50 lpm was injected as a central gas and a sheath gas into the high-frequency thermal plasma apparatus, respectively. Thereafter, 17 kW was applied to the plasma torch power source to generate a high-temperature thermal plasma, and the vacuum degree of the equipment before injecting the raw material powder was maintained at 500 torr. The raw material powder prepared through the injection nozzle of the plasma generating electrode portion was irradiated with high- Inside the reactor, the graphite moves without thermal damage by the plasma, and only the nickel powder undergoes selective vaporization to be crystallized into nanoparticles and bonded to the graphite. The combined particles of graphite and nickel nanoparticles were separated from the cyclone part and adsorbed to the filter of the collector through the transfer pipe. The powder adsorbed on the filter was collected in the rejection through the blowback process.

Subsequently, in order to form a catecholamine layer on the captured complex, 2 mM concentration of dopamine was dissolved in TBS (Tris buffer solution, 100 mM), and 5 g of the complex was mixed with 1 L of the solution, followed by stirring at room temperature for 2 hours Respectively. To increase the rate of reaction of dopamine with nickel nanoparticles, sodium periodate was added with 10% by weight of dopamine and stirred. After stirring for 2 hours, unreacted material was removed by filtration, washed twice with Di-water and dried at room temperature to prepare a graphite composite (hereinafter referred to as "GC") coated with polypodamine. The weight percentages of graphite, nanoparticles and polydodamine in the prepared graphite composites were 94.95 wt%, 5 wt% and 0.05 wt%, respectively. The average particle diameter of the nanoparticles identified through SEM photographs was 32 nm.

The prepared graphite composite and expandable graphite (denoted as 'EG' in Tables 1 to 3 below) were mixed at a weight ratio of 1: 9 to prepare a graphite composition. The graphite composition and the thermoplastic polymer, polyamide-6, , The mixture was poured into a main hopper and a site feeder of a twin-screw extruder in the same direction and melted at an extruder barrel temperature of 280 ° C to prepare pellets using a strand cutting method and then dried in a hot air dryer to prepare a master batch for a graphite composite material .

≪ Examples 2 to 18 >

And the graphite composition was changed as shown in Tables 1 to 3 to prepare master batches for graphite composite materials as shown in Tables 1 to 3 below. The graphite flakes in Table 1 to Table 3 were represented by "GF ", and those having an average particle size of 75 占 퐉 were used. Spherical graphites were represented by" RG ", and those having an average particle size of 40 占 퐉 were used.

≪ Comparative Example 1 &

The procedure of Example 1 was repeated to prepare a master batch for a graphite composite material containing only a graphite composite without adding graphite to the graphite composition.

≪ Comparative Example 2 &

Except that the same amount of carbon black having an average particle size of 330 nm was charged in place of the graphite of the graphite composition to prepare a master batch for a graphite composite material.

<Experimental Example>

The master batches prepared in Examples and Comparative Examples were put into a conventional injection apparatus to produce injection moldings, and the following properties were evaluated. The results are shown in Tables 1 to 3. At this time, the sizes and shapes of the specimens, which are the respective injection products, were manufactured so as to be suitable for the evaluation method of the following physical properties.

1. horizontal thermal conductivity

The horizontal thermal conductivity of the specimen was measured according to ASTM E1461.

2. Tensile strength

The tensile strength of the specimen was measured in accordance with ASTM D638.

3. Impact strength

The impact strength was measured in accordance with ASTM D256.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Graphite composition GC: graphite weight ratio 1: 9 1: 14.7 1:17 1: 24.5 1:26 1: 3 1: 1.2 Graphite type and mixing weight ratio EG EG EG EG EG EG EG Graphite composite PA-6: graphite composition weight ratio 1: 1 1: 1 1: 1 1: 1 1: 1 1: 1 1: 1 Horizontal thermal conductivity
(W / mK) 14.2 14.5 14.5 14.7 14.9 13.8 13.9 Tensile strength (Kgf / cm2) 855 860 830 810 790 840 830 Impact strength (Kgf.cm/cm) 3.52 3.53 3.20 3.18 2.58 3.52 3.35

(GC: graphite composite, EG: expanded graphite, PA-6: polyamide-6)

Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Graphite composition GC: graphite weight ratio 1: 0.7 1: 9 1: 9 1: 9 1: 9 1: 9 1: 9 Graphite type and mixing weight ratio EG GF RF EG + RG
/ 1: 8 EG + GF / 1: 8 EG + GF / 1: 13 EG + GF / 1: 15 Graphite composite PA-6: graphite composition weight ratio 1: 1 1: 1 1: 1 1: 1 1: 1 1: 1 1: 1 Horizontal thermal conductivity
(W / mK) 14.2 13.20 8.30 9.3 14.8 14.5 13.7 Tensile strength (Kgf / cm2) 790 820 670 710 840 855 832 Impact strength (Kgf.cm/cm) 2.71 2.93 3.62 3.45 3.69 3.60 3.49

(GC: graphite composite, EG: expanded graphite, GF: graphite flake, RF: spherical graphite, PA-6: polyamide-

(GC: graphite composite, EG: expanded graphite, GF: graphite flake, PA-6: polyamide-6)

As can be seen from Tables 1 to 3,

It can be confirmed that the tensile strength and the impact strength of Comparative Example 1 including only the graphite composite are significantly lower than those of the graphite composite according to the present invention.

Also, it can be confirmed that the thermal conductivity of Comparative Example 2 in which carbon black other than carbon material or graphite is contained is not significantly improved.

On the other hand, it can be confirmed that Example 1 including expanded graphite in graphite excellently exhibits both thermal conductivity and mechanical strength in comparison with Example 9 including graphite flake and Example 10 including spherical graphite, and graphite It can be seen that the combination of composite and expanded graphite has an increased effect.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100, 100 ': heat dissipation filler 101: graphite composite
102, 103: Graphite 200, 210, 220: Polymer matrix
211, 221: deep portions 212a, 212b, 222a, 222b:
300, 310, 3300: protective coating layer 400: pigment
500: second heat-radiating filler
1000, 1000, 2000, 2000, 3100: graphite composite
3000,3000 ': heat-radiating composite material 3200: supporting member

Claims (17)

A graphite composite in which nanoparticles having a catecholamine layer on its surface are fixed on the graphite; And graphite composition comprising at least one graphite flake, spherical graphite and expanding graphite. The method according to claim 1,
Wherein the graphite composite and the graphite are present in a weight ratio of 1: 1 to 25. The method according to claim 1,
Wherein the graphite composite further comprises at least a polymer layer coated on the catecholamine layer. The method according to claim 1,
Wherein the graphite composite has an average particle size of 10 to 900 占 퐉. The method according to claim 1,
Wherein the graphite flake has an average particle size of 10 mu m to 1,000 mu m, the expanded graphite has an average particle size of 50 mu m to 1,000 mu m, and the spherical graphite has an average particle size of 10 mu m to 100 mu m. The method according to claim 1,
Wherein the graphite is expanded graphite. The method according to claim 1,
Wherein the graphite comprises graphite flake and expanded graphite,
Wherein the expanded graphite and graphite flake are contained in a ratio of 1: 1 to 20 by weight. 3. The method of claim 2,
Wherein the graphite composite and the graphite are present in a weight ratio of 1: 1 to 15. 8. The method of claim 7,
Wherein the graphite comprises graphite flake and expanded graphite,
Wherein the expanded graphite and the graphite flake are contained in a weight ratio of 1: 1 to 13. 10. A graphite composition according to any one of claims 1 to 9; And
A master batch for the production of a graphite composite comprising a thermoplastic polymeric compound. 11. The method of claim 10,
Wherein the graphite composition comprises 20 to 80% by weight of the total weight of the master batch. 11. The method of claim 10,
The thermoplastic polymer compound may be at least one selected from the group consisting of polyamide, polyester, polyketone, liquid crystal polymer, polyolefin, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyphenylene oxide (PPO), polyether sulfone Masterbatches for the production of graphite composites which are one compound selected from the group consisting of acrylonitrile-butadiene-styrene copolymer (ABS), polyetherimide (PEI) and polyimide, or mixtures or copolymers of two or more thereof. A polymer matrix formed by molding a thermoplastic polymer compound; And
And a heat dissipation filler comprising the graphite composition according to claim 1 dispersed in the polymer matrix. 14. The method of claim 13,
And a protective coating layer is further provided on at least a part of the outer surface of the polymer matrix. A polymer matrix formed by molding a thermoplastic polymer compound to form a core portion and a cover portion surrounding the core portion;
A first heat-dissipating filler including the graphite composition according to claim 1 dispersed including the deep part; And
And a pigment dispersed in the inside of the covering portion. 16. The method of claim 15,
And the cover further comprises a second heat dissipation filler. A graphite composite according to any one of claims 13 to 16. And
And a support member configured to form at least one interface with the polymer matrix of the graphite composite.

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