KR20180125270A - Graphite-polymer composite material - Google Patents

Abstract

Provided is a graphite-polymer composite material. The graphite-polymer composite material according to an embodiment of the present invention comprises: a molecular matrix; a metal supporting layer forming at least one interface with the polymer matrix and including a plurality of anchor holes passing through upper and lower portions; and a heat dissipation filler dispersed in the polymer matrix. According to the above, the composite material exhibits excellent heat-dissipating performance and at the same time, the same can be applied to a supporting body and an outer housing of a heat source by securing mechanical strength. Further, since durability is excellent, the long time heat-dissipating performance can be exhibited. Further, since the composite material is excellent in light weight and economical efficiency, the same can be widely applied to various technical fields requiring heat dissipation.

Description

[0001] Graphite-polymer composite material [0002]

The present invention relates to a graphite-polymer composite material, and more particularly, to a graphite-polymer composite material having excellent heat dissipation performance, mechanical strength and durability, and a method for producing the same.

Heat accumulated in electronic components, lamps, transformer housings, and other unwanted heat generating devices can shorten operating life and reduce operating efficiency. In order to prevent this, a heat dissipating member such as a heat sink or a heat exchanger or a heat dissipating device is used together with an exothermic device, and a heat dissipating member or a heat dissipating device is usually used as a metal, come. However, there is a problem that the metal 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.

Among them, attempts have been made to perform the function of the outer housing of the heat source or to combine the function of the support with the heat dissipating member itself by taking into account the excellent moldability and heat dissipation of the heat dissipating member. However, due to the weak mechanical strength of the subject polymer resin itself There is a problem that it is difficult to perform the function of the outer housing or the support for protecting the heat source.

In order to solve this problem, attempts have recently been made to incorporate a support member capable of performing a support function into a heat dissipating member into a heat dissipating member. However, due to a lack of compatibility due to a heterogeneous material between the polymer compound and the support member, There is a problem that the polymer resin is broken or peeled during use as the separation occurs at the member interface.

Further, the spaced gaps may cause deterioration of the heat dissipation performance, and if the polymer compound is broken or peeled, the problem of deterioration of the heat dissipation performance may be further exacerbated.

Furthermore, when moisture permeates through the spaced gaps, the interface peeling is accelerated, and oxidization of the support member may be caused to lower the heat radiation performance and the mechanical strength.

Accordingly, it is urgently required to develop a heat dissipating member having excellent heat dissipation performance and mechanical strength and excellent durability by improving interfacial properties between dissimilar materials.

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

SUMMARY OF THE INVENTION It is an object of the present invention to provide a graphite-polymer composite material which can exhibit excellent heat radiation performance and at the same time has mechanical strength and can be applied to a support or an outer housing of a heat source.

Another object of the present invention is to provide a graphite-polymer composite material which is excellent in durability and can exhibit long-term heat radiation performance.

Furthermore, it is a further object of the present invention to provide a housing or a supporting member of various articles through a graphite-polymer composite excellent in heat radiation, mechanical strength and durability.

In order to solve the above problems, the present invention provides a polymer matrix; A metal supporting layer forming at least one interface with the polymer matrix and including a plurality of anchor holes passing through upper and lower portions; And a heat-dissipating filler dispersed in the polymer matrix.

According to an embodiment of the present invention, the cross section of the anchor hole may be at least one of a regular shape or an irregular shape selected from the group consisting of a circle, an ellipse, a triangle, a square, a cross and a star.

Further, the diameter of the anchor holes may be 1 mm or more.

Also, at least a portion of the anchor holes may be filled with the polymer matrix.

Further, the metal support layer may further include a protrusion formed to extend from at least a part of the anchor hole edge of a part or all of the anchor holes.

Further, the projecting portion may be a cut-away piece in which at least a part of the metal supporting layer is cut.

In addition, a part of the protrusion may protrude upward from the metal support layer, and the remainder may protrude downward from the metal support layer.

The heat-radiating filler may include a graphite composite having nanoparticles bonded to a graphite surface and a catecholamine layer coated with the nanoparticles.

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

Also, the graphite composite may have an average particle size of 50 to 600 mu m.

In addition, the heat-radiating filler may further include at least one of graphite flake, expanded graphite and spherical graphite for preventing agglomeration of the graphite composite. At this time, the graphite flake, expanded graphite or spherical graphite may have an average particle size of 50 to 300 탆.

At least one of the graphite flake, the expanded graphite and the spherical graphite may be included in an amount of 5 to 200 parts by weight based on 100 parts by weight of the graphite composite.

In addition, the polymer matrix may be selected from the group consisting of polyamides, polyesters, polyketones, liquid crystal polymers, polyolefins, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyphenylene oxide (PPO), polyether sulfone , Polyetherimide (PEI) and polyimide, or a mixture or copolymer of two or more species.

The metal support layer may be one metal selected from the group consisting of aluminum, magnesium, iron, titanium, and copper, or an alloy including at least one metal.

The outer surface of the polymer matrix may further include a protective coating layer.

Also, the protective coating layer may be a heat-dissipating coating layer.

The present invention also provides a heat dissipation housing including the graphite-polymer composite according to the present invention.

The present invention also provides a heat dissipation supporting member comprising a graphite-polymer composite.

According to the present invention, the graphite-polymer composite exhibits excellent heat-radiating performance and at the same time, it can be applied to a supporting body and an outer housing of a heat source by securing mechanical strength. In addition, since it is excellent in durability, it can be exposed to external physical and chemical stimuli such as moisture and heat for a long time without deteriorating the heat dissipation / mechanical strength. Therefore, it is widely applied to various technical fields requiring heat dissipation and mechanical strength .

1 is a sectional view of a graphite-polymer composite according to an embodiment of the present invention,
2 is a plan view of a metal support layer included in an embodiment of the present invention,
3A to 3E are views showing various shapes of anchor holes formed in a metal supporting layer included in an embodiment of the present invention,
4 to 6 are sectional views of a graphite-polymer composite according to various embodiments of the present invention,
FIG. 7A is a perspective view of a graphite composite, FIG. 7B is a cross-sectional view taken along a line X-X 'in FIG. 7A, and FIG.
FIG. 8 is a schematic view illustrating a bonding interface between a heat-radiating filler and a metal support layer included in an embodiment of the present invention, and
9 is a cross-sectional view of a graphite composite which is a heat-radiating filler included in an embodiment of the present invention.

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.

Referring to FIG. 1, a graphite-polymer composite material 1000 according to an embodiment of the present invention includes a polymer matrix 200, a metal support layer 300 forming at least one interface with the polymer matrix 200, And a heat dissipation filler (100) dispersed on the polymer matrix.

First, the polymer matrix 200 will be described.

The polymer matrix has good compatibility with the metal supporting layer 300 and the heat-radiating filler 100 described later, and is preferably formed by a polymer compound capable of injection molding without affecting the dispersion of the heat- There is no limitation. As a preferable example, the polymer matrix 200 may be a known thermoplastic polymer compound. The thermoplastic polymer compound is preferably selected from the group consisting of polyamides, polyesters, polyketones, liquid crystal polymers, polyolefins, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyphenylene oxide (PPO) PES), 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.

Next, the metal supporting layer 300 will be described.

The metal support layer 300 is a layer that exhibits a predetermined heat dissipation performance while securing mechanical strength to the composite material 1000. The metal support layer 300 is excellent in compatibility with the polymer matrix and is not easily separated from the interface between the polymer matrix 200 and the metal support layer 300. The metal support layer 300 has excellent mechanical strength at a thin thickness and can be injection- And a metal material having a predetermined thermal conductivity can be used without limitation. As a non-limiting example, the metal support layer 300 may be one metal selected from the group consisting of aluminum, magnesium, iron, titanium, and copper, or an alloy including at least one metal.

However, due to material differences between the polymer matrix 200 and the polymer matrix 200, the bonding property at the interface between the polymer matrix 200 and the metal support layer 300 may be poor. As a result, Cracks and peeling of the matrix 200 may occur, and water and air may flow into the separated gap, which may cause corrosion of the metal supporting layer 300.

In order to enhance the interfacial properties of the polymer matrix 200 and the metal support layer 300 in contact with each other to enhance the bonding strength between the polymer matrix 200 and the metal support layer 300, the metal support layer 300 includes a plurality of anchor holes H, The polymer matrix 200 can be filled in the anchor hole H in the graphite-polymer composite material so that the bonding force between the polymer matrix 200 and the metal support layer 300 can be structurally increased.

The anchor hole H formed in the metal support layer 300 may have a diameter enough to allow the polymer matrix 200 to be easily filled in the anchor hole H by penetrating the polymer matrix 200. For example, (D in Fig. 2) may be 1 mm or more, preferably 1 to 50 mm, more preferably 1 to 30 mm, and further preferably 1 to 10 mm. If the diameter of the anchor hole (H) is less than 1 mm, the polymer matrix may penetrate into the anchor hole and may not be completely filled. If the anchor holes are not completely filled, the bonding strength of the interface may be insignificant, and there may be a fear that the heat radiation performance may be deteriorated due to the occurrence of the adiabatic effect due to the air filled in the void spaces inside the anchor holes. If the diameter of the anchor hole H exceeds 50 mm, the interfacial bonding property between the polymer matrix and the metal support layer may be improved, but the heat dissipation property due to the metal support layer may be deteriorated and the mechanical strength may decrease .

The anchor holes H are distributed at uniform intervals along the width and the longitudinal direction of the metal support layer 300 or at different intervals between the anchor holes H for each position so that eventually, The distribution ratio at which the holes H are provided can be different. The interval (p in FIG. 2) between the anchor holes H may be, for example, 5 to 20 mm. As the anchor holes H are formed with narrow intervals, the bonding properties can be improved. However, there is a fear that the heat dissipation performance and the mechanical strength of the metal support layer deteriorate.

The anchor holes H may be at least one of a regular shape (see FIG. 2, FIG. 3A to FIG. 3E) or an irregular shape selected from the group consisting of circular, elliptical, triangular, rectangular, In addition, the cross-sectional shapes of the plurality of anchor holes H provided in the metal support layer 300 may all be the same, some or all different.

Since the anchor holes H can be formed through punching by a known method, a detailed description of the forming method of the present invention will be omitted.

As shown in FIGS. 4 to 6, the graphite-polymer composite materials 1001, 1002, and 1003 are used as metal support layers 301, 302, and 303 to exhibit improved bonding properties with the polymer matrix 200, 311, 312, 313, and 314 formed to extend from at least a portion of the edge. The protrusions 311, 312, 313 and 314 function as an anchors in the polymer matrix 200 so that the bonding properties between the polymer matrix 200 and the metal support layers 301, 302 and 303 can be structurally further improved together with the above-described anchor holes H and H ' have.

The protrusions 311, 312, 313, and 314 may be formed by punching, stamping, or pressing the upper side of the metal support layers 301, 302, and 303 to cut the punching, stamping, or pressurized portions. However, the method of forming the protrusions 311, 312, 313, and 314 is not limited thereto, and may be formed in various ways as long as at least a portion of the metal supporting layers 301, 302, and 303 protrude from the edge of the anchor groove H.

4, the protrusions 311, 312, 313, and 314 may extend from the entire periphery to protrude upward, or may extend upward from the first line segment as shown in FIGS. 5 and 6, and protrude upward.

The protrusions 311, 312, 313, and 314 may have a bent shape as shown in FIGS. 5 and 6, and the bonding characteristics between the polymer matrix 200 and the metal supporting layers 301, 302, and 303 may be structurally further increased. The shape in which the protrusions 311, 312, 313, and 314 are bent is not limited to FIGS. 5 and 6, and it is possible to further improve the structural bonding property by having a structurally complicated shape without being difficult to manufacture.

6, a portion of the protrusions 313 and 314 provided on the metal supporting layer 303 may protrude upward, and the rest may protrude downward, through which the metal supporting layer 303 is formed, It is possible to improve the interfacial bonding property between the respective portions of the polymer matrix 200 located in the metal matrix layer 200 and the portions of the polymer matrix 200 located below the metal support layer 302 as shown in FIG. 302) lower surface can be prevented.

As shown in FIGS. 1, 4 and 6, the metal supporting layers 300, 301, and 303 may be formed so that the entire surface is surrounded by the polymer matrix 200, or the lower surface of the metal supporting layer 302 (Not shown) such that the upper surface of the metal support layer is in contact with the polymer matrix and the side surface and the lower surface of the metal support layer are exposed. The specific position of the metal support layer in the polymer matrix 200 Is not particularly limited in the present invention.

The thickness of the metal support layers 300, 301, 302, and 303 may be 0.5 to 90% or more of the total thickness of the graphite-polymer composite materials 1000, 1001, 1002, and 1003. If the thickness of the metal support layers 300, 301, 302 and 303 is less than 0.5% of the total thickness of the graphite-polymer composite 1000, 1001, 1002 and 1003, it may be difficult to secure the desired level of mechanical strength, It is difficult to exhibit a desired level of heat radiation performance, particularly radiation characteristics, and the formability into a complicated shape may also be deteriorated. However, the present invention is not limited thereto, and the thickness of the metal support layers 300, 301, 302, and 303 may be appropriately changed in consideration of the mechanical strength required for the graphite-polymer composite material.

The metal support layers 300, 301, 302, and 303 may be formed in a bar shape having a predetermined aspect ratio, a plate shape having a predetermined width, a border wire having a predetermined shape such as a square shape or a circle, or a plurality of wires or bars , A parallel structure, a lattice structure, a honeycomb structure, and a variety of structures in which they are mutually combined.

Next, the heat dissipation filler 100 dispersed in the polymer matrix 200 will be described.

The heat-radiating filler 100 may be a filler formed of a material known to be thermally conductive and may be used without limitation, and may be a metal, an alloy, a ceramic, and a carbon-based filler. The heat dissipation pillar 100 preferably includes nanoparticles 20 bonded to the graphite surface 10 and a catecholamine layer 30 coated with the nanoparticles 20 as shown in Figures 7A and 7B. And a graphite composite (101).

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 natural graphite, for example, it may be expanded graphite expanded graphite. 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.

Also, the average particle size of the graphite 10 may be 50 to 600 mu m, for example, 300 mu m.

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 are mediums capable of providing the graphite 10 with a catecholamine layer 30 described later, and at the same time the graphite composite 101 is supported on the metal support layer 300 And functions as an anchor when the interface is formed, thereby preventing the polymer matrix 200 from being separated from the metal support layer 300 due to the graphite composite 101.

First, the medium for forming the catecholamine layer 30 will be described. Since the functional group capable of mediating a chemical reaction is hardly provided on the surface of the graphite 10 described above, the graphite 10 in the polymer matrix, which is a different material, It is difficult to disperse, and the inserted graphite is easy to aggregate. A method of providing a catecholamine layer on a graphite by a method of preventing this and improving the dispersibility in a polymer matrix may be considered. However, even a catecholamine-based compound known to have excellent compatibility with miscellaneous materials and compatibility with other materials, There is a problem that the amount of the catecholamine compound remaining in the graphite is very small even when the catecholamine compound is treated on the graphite. Further, in order to solve this problem, there is a limitation in increasing the amount of the catecholamines based on the surface of the modified graphite, even if a modification treatment is carried out to provide a functional group on the surface of the graphite.

However, in the case of the graphite 10 having the nanoparticles 20 on its surface, there is an advantage that the catecholamines can be introduced into the graphite by the desired amount as the catecholamines are easily bonded on the surface of the nanoparticles.

Next, the function as the anchor of the nanoparticles 20 will be described. The metal support layers 300, 301, 302, and 303 provided to improve the mechanical strength of the graphite composite may be formed by a heat dissipation filler and / or a lack of compatibility with a polymer compound of a different material. If the heat dissipation filler is disposed adjacent to the metal support layer, When the interface is formed, since the interface has almost no bonding force, the polymer matrix 200 is easily separated from the metal support layer 300 at the interface portion. Referring to FIG. 8, in the case of the heat dissipation filler 102 having no nanoparticles formed thereon, an interface may be formed by abutting against the metal support layer 300. Due to the heterogeneous material, The spacing may occur at the interface (B), and the generated spacing may cause a larger spacing due to vibration or the like, and cracking and peeling of the polymer matrix 200 may eventually occur at the corresponding portions. In addition, when the metal support layer 300 has a poor interfacial bonding strength with the polymer matrix 200, which is a heterogeneous material, when the period of use of the graphite-polymer composite material is prolonged, the interfacial adhesion between the metal support layer 300 and the polymer matrix may be peeled off There is a concern.

However, in the case of the graphite composite 101 in which the nanoparticles 20 are formed on the graphite 10, the nanoparticles 20 function as anchors at the interface between the graphite 10 and the metal support layer 300, And the interfacial bonding characteristics may be more advantageous when the material of the nanoparticles 20 is a metal. Therefore, the interface between the heat-radiating filler / metal support layer and / or the polymer matrix / metal support layer The separation phenomenon can be remarkably reduced.

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 10 to 500 nm, preferably 10 to 300 nm.

In addition, the nanoparticles 20 may be provided in an amount of 10 to 70% area, more preferably 30 to 70% of the entire surface area of the individual graphite 10, have. The nanoparticles 20 may be present in an amount of 5 to 70% by weight, preferably 20 to 50% by weight based on the total weight of the graphite composite 101. At this time, the nanoparticles 20 are chemically bonded to the graphite 10 to exhibit stronger binding force.

Next, the catecholamine layer 30 provided on the surface of the nanoparticles 20 will be described. The catecholamine layer 30 improves the fluidity and dispersibility of the graphite and the interfacial bonding property between the graphite composite and the polymer compound in the polymer compound of different materials and at the same time the graphite composite 101 improves the fluidity, The gap between the graphite composite 101 and the metal support layers 300, 301, 302, and 303 may be improved at the interface so that the separation of the polymer matrix 200 from the surface of the metal support layer 300 may be significantly reduced . 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, the polymer layer 40 may function as a bonding material capable of introducing the polymer layer 40 into the graphite 10 to exhibit further improved dispersibility in the polymer compound.

The catecholamine-based compound forming the catecholamine layer 30 is an ortho-group of the benzene ring, meaning a single molecule having a hydroxy group (-OH) and various alkylamines in the para- group As a non-limiting example of various derivatives of such structures, include, but are not limited to, dopamine, dopamine-quinone, epinephrine, alphamethyldopamine, norepinephrine, Such as alphamethyldopa, droxidopa, indolamine, serotonin or 5-hydroxydopamine, and the like, for example, the catecholamine layer 30 may be dopamine or a 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.

9, a polymer layer 40 'may be further coated on the catecholamine layer 30' of the graphite composite 101 ', and a polymer compound 40' may be formed on the catecholamine layer 30 ' And compatibility, and further improved fluidity, dispersibility of heat-radiating filler, and interfacial bonding properties can be realized. 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 0.1 to 1000 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 can be produced by forming nanoparticles on a graphite surface and forming a catecholamine layer on the nanoparticles, thereby forming a polymer layer on the catecholamine layer. . ≪ / RTI >

First, the step of forming the nanoparticles on the graphite surface can be employed without limitation as long as it is a known method of forming nanoparticles on the surface of the graphite. As a non-limiting example, As a synthesis technique, inert gas condensation (IGC), chemical vapor condensation (CVC), metal salt spray-drying, etc. may be employed. However, the inert gas condensation (IGC) process can produce extremely fine nanoparticle powder 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- 200 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. Also, 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. In addition, 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.

Thereafter, the step of forming a catecholamine layer on the graphite on which the nanoparticles are formed is performed. Specifically, the step of dipping the graphite on which the nanoparticles are formed in the weakly basic aqueous solution of dopamine is performed. And forming a poly-dopamine layer on the surface of the graphite having the nanoparticles formed thereon.

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 dipping graphite in which nanoparticles are formed in a 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 in which nanoparticles are formed. 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.

In this case, the dipping time determines the thickness of the polypodamine layer. When a dopamine aqueous solution having a pH of 8 to 14 and a dopamine concentration of 0.1 to 5 M is used, the dipping time is preferably about 0.5 to 24 It is desirable to dive for a period of time. 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.

Thereafter, a polymer layer may be further formed on the catecholamine layer. The polymer layer may be formed by dipping the polymer layer forming composition to form a graphite composite in which a catecholamine layer is formed. However, the present invention is not limited to this, and it is possible to use a known method such as a blade coating, a flow coating, a casting, a printing method, a transfer method, a brushing, or a spraying, Layer can be formed. The composition for forming a polymer layer may be a dissolving solution or a molten melt in which a desired polymer compound is dissolved. At this time, the thickness of the polymer layer formed may be appropriately changed in consideration of the material properties such as compatibility between the polymer compound forming the polymer layer and the polymer compound forming the polymer matrix.

The graphite-polymer composite materials 1000, 1001, 1002, and 1003 according to an embodiment of the present invention are formed of a heat dissipation filler 100 to suppress aggregation of the graphite composite 101, 200, and may further include at least one of graphite flake, expanded graphite, and spherical graphite for implementation of a lighter weight composite. The above-described graphite composite may further include a catecholamine layer to improve fluidity, dispersibility, and interface bonding characteristics when mixed with a polymeric compound. However, when the content of the catecholamine layer is increased, It is possible to prevent agglomeration between the composites by providing at least one of the graphite flake, expanded graphite and spherical graphite, and it is possible to prevent the composite material from having uniform mechanical strength, heat radiation characteristics, It is possible to exhibit physical properties such as shielding. In addition, the spherical graphite improves the vertical thermal conductivity of the graphite-polymer composite material, and the expanded graphite can further improve the thermal conductivity of the graphite-polymer composite material.

At least one of the graphite flake, the expanded graphite and the spherical graphite may have an average particle size of 50 to 300 탆.

Also, at least one of the graphite flake, expanded graphite and spherical graphite may be included in an amount of 5 to 200 parts by weight based on 100 parts by weight of the graphite composite. If the heat-radiating filler other than the graphite composite is provided in an amount of less than 5 parts by weight, improvement of the heat radiation performance depending on the different kinds of heat-radiating fillers is insignificant and the aggregation of the graphite composite may be difficult to prevent, There is a possibility of cost increase due to the necessity of providing a composite material, which may be undesirable for lightening the composite material to be realized. If the heat-radiating filler is present in an amount of more than 200 parts by weight, the composite material may fail to exhibit a desired level of thermal conductivity and mechanical strength, and the interfacial bonding property may deteriorate, The spacing between the fibers can be more frequent and worsened and the fluidity of the heat dissipation pillar can be concentrated at the central portion of the composite material than in the surface portion of the composite material during the manufacturing process of the composite material,

The graphite-polymer composite material 1000 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 improving agent, a coupling agent, a UV absorbent, 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 graphite-polymer composite, and examples thereof include carbon fibers, glass fibers, glass beads, zirconium oxide, wollastonite, In the group consisting of gibbsite, boehmite, magnesium aluminate, dolomite, calcium carbonate, magnesium carbonate, mica, talc, silicon carbide, kaolin, calcium sulfate, barium sulfate, silicon dioxide, ammonium hydroxide, magnesium hydroxide and aluminum hydroxide One or more selected components may be included as strength modifiers. The strength improver may be included in an amount of 0.5 to 200 parts by weight based on 100 parts by weight of the heat-radiating filler, but is not limited thereto. For example, when the strength modifier is glass fiber, the diameter of the glass fiber may be 2 to 8 mm.

In addition, the impact modifier can 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 graphite-polymer composite. For example, the impact modifier may be a thermoplastic resin. For example, it may be a rubber-based resin. The rubber-based resin may be natural rubber or synthetic rubber. The synthetic rubber may be selected from the group consisting of styrene butadiene rubber, butadiene rubber, chloroprene rubber, isoprene rubber, isobutene isoprene rubber, , IIR), acrylonitrile-butadiene rubber (NBR), ethylene propylene rubber (EPR), ethylene propylene diene monomer rubber, acrylic rubber, silicone rubber, Fluorine rubber, urethane rubber, and the like, but not limited thereto.

In addition, the impact modifier may be a core / shell structure elastic particle. For example, the core may be an allyl type resin, and the shell portion may be a polymer resin having a functional group capable of reacting with the thermoplastic polymer compound so as to increase compatibility and bonding strength. The impact modifier may be included in an amount of 0.5 to 200 parts by weight based on 100 parts by weight of the heat-radiating filler, but is not limited thereto.

In addition, the antioxidant is provided for preventing the main chain of the polymer compound forming the polymer matrix by the shearing at the time of extrusion and injection, for example, the thermoplastic polymer compound from breaking, and preventing heat discoloration. 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 polymer compound forming the polymer matrix.

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 polymer compound forming the polymer matrix.

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 polymer compound forming the polymer matrix.

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 polymer compound forming the polymer matrix.

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 1.0 part by weight based on 100 parts by weight of the polymer compound forming the polymer matrix.

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 polymer compound forming the polymer matrix.

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 included in an amount of 0.01 to 3.0 parts by weight based on 100 parts by weight of the polymer compound forming the polymer matrix.

In addition, the coupling agent may be a known coupling agent without limitation, and as an example thereof, maleic acid grafted polypropylene may be used. The coupling agent may be contained in an amount of 0.01 to 10.0 parts by weight based on 100 parts by weight of the polymer compound forming the polymer matrix.

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'- Sulfonyl imide potassium salt, or a mixture thereof. The flame retardant may be contained in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the polymer compound forming the polymer matrix.

The graphite-polymer composite materials 1000, 1001, 1002, and 1003 according to an embodiment of the present invention may be prepared by coating or impregnating the metal supporting layers 300, 301, 302, and 303 with a solution or melt of a polymer compound including a dispersed heat- , Extrusion, and the like, followed by solidification such as curing, drying and / or cooling. In the case of the concrete production method, a method and a method may be used depending on the concrete type of the polymer compound forming the polymer matrix The present invention is not particularly limited to this.

In addition, the graphite-polymer composite material 1000, 1001, 1002, and 1003 may further include a protective coating layer 400 on the outer surface of the polymer matrix 200. The protective coating layer 400 prevents separation of the heat-radiating filler 100 located on the surface of the polymer matrix, prevents scratches due to physical stimulation on the surface, provides an insulating function according to the material, It is possible to use it in applications such as electronic devices which are simultaneously required.

The protective coating layer 400 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 400 may have a thickness of 0.1 to 1000 탆, but the protective coating layer 400 may be modified according to the purpose.

Meanwhile, the protective coating layer 400 may interfere with the radiation of the heat conducted through the heat-radiating filler 100 and the metal support layer 300. The protective coating layer 400 may be a heat-radiating coating layer further including a heat-radiating filler in order to exhibit heat dissipation, particularly, heat radiation to the outside air. The heat-radiating filler can be used without limitation in the case of a known heat-radiating filler. If the insulation is simultaneously required, at least one insulating heat-radiating filler selected from the group consisting of aluminum oxide, boron nitride, talc, magnesium oxide, silicon carbide, .

The kind, particle diameter, content, etc. of the heat-radiating filler provided in the protective coating layer 400 may be designed differently according to the purpose, and thus the present invention is not particularly limited thereto.

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.

10: graphite 20: nanoparticles
30: catecholamine layer 40: polymer layer
100: heat dissipation filler 101: graphite composite
102: non-graphite composite 200: polymer matrix
300, 301, 302, 303: metal supporting layer 311, 312, 313, 314:
400: protective coating layer
1000,1001,1002,1003: Graphite-polymer composite

Claims (16)

Polymer matrix;
A metal supporting layer forming at least one interface with the polymer matrix and including a plurality of anchor holes passing through upper and lower portions; And
And a heat dissipation filler dispersed in the polymer matrix. The method according to claim 1,
Wherein the cross-section of the anchor hole is at least one of a regular shape or an irregular shape selected from the group consisting of a circle, an ellipse, a triangle, a square, a cross, and a star. The method according to claim 1,
Wherein the diameter of the anchor holes is at least 1 mm. The method according to claim 1,
And at least a part of the anchor holes is filled with the polymer matrix. The method according to claim 1,
Wherein the metal support layer comprises protrusions extending from at least a portion of an anchor hole edge of the part or the whole of the graphite-polymer composite. 6. The method of claim 5,
Wherein the protrusions are discrete pieces in which at least a part of the metal supporting layer is cut. 6. The method of claim 5,
Wherein a part of the projecting portion protrudes toward the upper side of the metal supporting layer and the remainder protrudes toward the lower side of the metal supporting layer. The method according to claim 1,
Wherein the heat dissipation filler comprises a graphite composite comprising nanoparticles bonded to a graphite surface and a catecholamine layer coated with the nanoparticles. The method according to claim 1,
Wherein the graphite composite further comprises at least a polymer layer covering the catecholamine layer. The method according to claim 1,
Wherein the graphite composite has an average particle size of 50 to 600 탆. The method according to claim 1,
The polymer matrix may be selected from the group consisting of polyamides, polyesters, polyketones, liquid crystal polymers, polyolefins, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyphenylene oxide (PPO), polyether sulfone (PEI) and polyimide, or a mixture or copolymer of two or more kinds of graphite-polymer composites. The method according to claim 1,
Wherein the metal support layer is an alloy containing one kind of metal selected from the group consisting of aluminum, magnesium, iron, titanium, and copper, or at least one kind of metal. The method according to claim 1,
And a protective coating layer is further provided on the outer surface of the polymer matrix. 14. The method of claim 13,
Wherein the protective coating layer is a heat radiating coating layer. A heat dissipation housing comprising a graphite-polymer composite according to any one of the preceding claims.  A heat radiation supporting member comprising the graphite-polymer composite according to any one of claims 1 to 14.

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