KR102258483B1 - A composite material composition having electromagnetic wave shielding function and a shaped product comprising the same - Google Patents

Abstract

The present invention relates to a composite material composition having an electromagnetic wave shielding function, and the present invention may include 67.2 to 75.2 wt% of a thermoplastic plastic and 24.0 to 32.0 wt% of a conductive filler. According to the present invention, it is possible to provide a composition having an excellent electromagnetic wave shielding function without an increase in the conductive filler content, and a composition having excellent electromagnetic wave shielding function and excellent mechanical properties, flowability, and moldability at the same time can be provided.

Description

A composite material composition having an electromagnetic wave shielding function and a molded article comprising the same {A COMPOSITE MATERIAL COMPOSITION HAVING ELECTROMAGNETIC WAVE SHIELDING FUNCTION AND A SHAPED PRODUCT COMPRISING THE SAME}

The present invention relates to a composite material composition having an electromagnetic wave shielding function, and more particularly, to a composition including a thermoplastic plastic and a conductive filler.

Due to the development of the Internet and communication technology, the market for mobile products is rapidly increasing, and accordingly, various electronic products and electronic components are rapidly miniaturized, lightweight, highly integrated, and high-performance. One of the most important factors determining the operability, stability, reliability, etc. of these electronic products and electronic components is electromagnetic interference (EMI).

Due to electromagnetic interference, unpredictable malfunctions of electronic products are emerging in the industry, and many studies have been published that electromagnetic waves have a negative effect on the human body, and countries around the world, including Korea, are strengthening regulations on the level of electromagnetic waves. . Accordingly, the need for an electromagnetic wave shielding function to prevent electromagnetic interference between electronic devices or to prevent electromagnetic waves from reaching the human body is greatly increasing in the industry.

In particular, in the automobile industry, the importance of the electromagnetic wave shielding function is emerging due to the electricization of automobile parts and the increase of eco-friendly automobiles. Conventionally, a metal material has been mainly used for electromagnetic wave shielding. Metal has high electrical conductivity compared to other materials and has excellent electromagnetic wave reflection properties, so it has been used as an electromagnetic wave shielding material in various fields.

However, metal is expensive and heavy due to its high specific gravity, and complicated shapes are difficult to process, which is disadvantageous in terms of productivity and production cost. In particular, due to the recent demand for weight reduction, which is an important issue in the automobile industry, there is an urgent need for a material that can replace heavy metal.

Korean Patent No. 10-1579522 discloses a composite material composition having an electromagnetic wave shielding function by adding a conductive filler such as carbon fiber or semigraphene to a thermoplastic plastic (Patent Document 1).

In general, since the content of conductive filler added to non-metal thermoplastics and the value of the electromagnetic wave shielding function of the composite material composition are proportional to each other, a high content of the conductive filler must be added to achieve a high level of electromagnetic wave shielding function. However, in this case, the specific gravity of the composite material composition increases, mechanical properties such as tensile strength are lowered, flowability is lowered, and the moldability of the product is lowered during extrusion or injection processing.

As disclosed in Patent Document 1, as a result of increasing the semi-graphene content in the composite material composition to 10, 20, or 30 wt%, the electromagnetic wave shielding effect increased to 18, 19, and 22 dB, while the tensile strength was 166, 116, 84 MPa It can be seen that there is a sharp decrease in Since the flexural strength is also sharply lowered to 203, 163, and 139 MPa, it is expected that the flowability of the composition and the moldability of the product will also be significantly reduced (Examples 1 to 3).

Patent Document 1: Republic of Korea Patent Publication No. 10-1579522

An object of the present invention is to provide a composition having an excellent electromagnetic wave shielding function without increasing the content of the conductive filler.

Another object of the present invention is to provide a composition having excellent electromagnetic wave shielding function and excellent mechanical properties, flowability, and moldability.

Another object of the present invention is to provide a composition having an excellent electromagnetic wave shielding function, which can be used for automotive electrical components, housings for electrical and electronic components, and in particular, can be effectively used for LDM (LED Driving Module) housings.

In order to achieve the above object, the present invention may contain 67.2 to 75.2% by weight of a thermoplastic plastic and 24.0 to 32.0% by weight of a conductive filler.

Preferably, the conductive filler may include 20.0 to 25.0 wt% of carbon fiber.

Preferably, the conductive filler may include 25.0 wt% of carbon fiber.

Preferably, the conductive filler may include 3.0 to 6.0 wt% of COOH functionalized graphene nanoplates (GNP).

Preferably, the conductive filler may include 6.0 wt% of COOH functionalized graphene nanoplates (GNP).

Preferably, the thermoplastic plastic is polybutylene terephthalate (PBT), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), polyamide (PA), polycarbonate (PC), modified polyphenylene oxide ( MPPO), polyphenylenesulfide (PPS), or mixtures thereof.

Preferably, the conductive filler may be selected from the group consisting of carbon fiber, carbon black, graphene nanoplates (GNP), COOH functionalized graphene nanoplates (GNP), or mixtures thereof.

The present invention may include a molded article prepared by including a composite material composition having an electromagnetic wave shielding function.

The present invention can provide a composition having an excellent electromagnetic wave shielding function without increasing the content of the conductive filler.

The present invention can provide a composition having excellent electromagnetic wave shielding function and excellent mechanical properties, flowability, and moldability at the same time.

The present invention can provide a composition having an excellent electromagnetic wave shielding function, which can be used for automobile electronic parts, housings for electric and electronic parts, and in particular can be effectively used for LED Driving Module (LDM) housings.

1 is a schematic diagram of generating COOH-functionalized GNPs by reacting graphene nanoplates (GNPs) with carboxylic acids (R-COOH).
2 is a graph comparing the electromagnetic wave shielding effect shown as a result of Examples 1 to 4 of the present invention (a horizontal axis frequency unit: GHz, vertical axis electromagnetic wave shielding effect unit: dB).

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, and the objects and effects of the present invention may be naturally understood or made clearer by the following description, but the objects and effects of the present invention are not limited only by the following description. . Meanwhile, in the description of the present invention, if it is determined that the description of the known technology related to the present invention may obscure the gist of the present invention, the detailed description thereof will be omitted.

The "molded article" used in the present invention has excellent electromagnetic wave shielding function or is excellent in electromagnetic wave shielding function and at the same time is manufactured including a composition excellent in mechanical properties, flowability, and moldability, such as pellets, films, It may include various molding (processing) forms, such as a sheet form.

In the composite material composition constructed through the best embodiment (Example 7) disclosed in Patent Document 1, 45% by weight of the conductive filler was added to the thermoplastic plastic, and the electromagnetic wave shielding effect was 55 dB. However, due to the high conductive filler content, it has poor mechanical properties, flowability, and formability, such as tensile strength of only 82 MPa, making it difficult to apply to various industries, and especially difficult to apply to the automobile industry requiring high level of mechanical properties. there is On the other hand, in the embodiment (Example 1) in which the conductive filler content was relatively lowered to 40 wt%, the tensile strength was excellent as 166 MPa, but the electromagnetic wave shielding effect was poor as 18 dB, so the marketability is still low. In other words, the most difficult thing in developing a composite material composition for electromagnetic wave shielding that can be used to replace metals and which can be applied to various industries is that the content of conductive fillers is reduced as much as possible (that is, without lowering the content of thermoplastics) and excellent levels of to have an electromagnetic wave shielding effect.

In order to solve these difficulties, the present invention has focused research on specifying and selecting carbon-based materials included in the conductive filler, and in particular, COOH-functionalized graphene nanoparticles that can obtain high dispersibility in thermoplastics even when using a low content. The study focused on characterizing and selecting plates (GNPs). It will be described in detail below.

The thermoplastic plastic constituting the composition of the present invention is polybutylene terephthalate (PBT), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), polyamide (PA), polycarbonate (PC), modified polyphenyl It may be selected from the group consisting of renoxide (MPPO), polyphenylenesulfide (PPS), or mixtures thereof.

Polybutylene terephthalate (PBT) contains an ester bond in the polymer main chain, and is widely used in automobile parts due to its excellent rigidity, toughness, abrasion resistance, chemical resistance, oil resistance, and moldability. It is widely used for parts around automobile lamps. PBT may have an average molecular weight of 10,000 to 200,000 g/mol, preferably 15,000 to 35,000 g/mol. Within the above range, mechanical properties, flow properties, and moldability are all excellent.

The conductive filler constituting the composition of the present invention may be selected from the group consisting of carbon fibers, carbon black, graphene nanoplates (GNP), COOH functionalized graphene nanoplates (GNP), or mixtures thereof.

As the carbon fiber, one made of pitch, rayon, or polyacrylonitrile (PAN) may be used. The carbon fiber preferably has a carbon content of 90% by weight or more and an average length of 5 to 7 mm. When the average length is less than 5 mm, mechanical properties are greatly reduced, and when it exceeds 7 mm, dispersion between materials becomes unfavorable, resulting in product molding sex is lowered In the present invention, in particular, chopped carbon fiber coated with an epoxy resin, a polyurethane resin, or a polyamide resin on the surface of the carbon fiber may be used. When coated with another polymer resin, the adhesion between the carbon fiber and the resin decreases, so that the carbon fiber Since it cannot induce even dispersion of the composite material, it may be a factor to deteriorate the physical properties of the composite material composition. The carbon fiber may be 20 to 25 wt%, and excellent electromagnetic wave shielding function, mechanical properties, flowability, and product formability can be obtained simultaneously within the above range.

Carbon black is made of spherical particles and does not need to be particularly limited, and any commercially available products such as furnace black, acetylene black, and Ketjen black can be used. Since carbon black has electrical conductivity, it is generally added to thermoplastic plastics to provide an electromagnetic wave shielding function. It is preferable to select a product with a high bonding area with the thermoplastic plastic because of its large specific surface area.

Graphene is a material that uses carbon-based graphite as a raw material and is spotlighted as a dream new material that can replace metal. The sp ^{2 hybrid orbital present in graphene is the sp 2} orbital of three adjacent atoms. This is because the free movement of electrons is possible through the formation of a strong sigma bond with the Graphene Nano Plate (GNP) is a form in which graphene is combined within 5 layers, and has properties similar to pure graphene, and thus has very excellent electrical and thermal conductivity properties. However, GNPs easily agglomerate due to the action of Van der walls force between them, and as they have a very stable chemical structure, it is difficult to be dispersed in thermoplastics because it is not easy to combine with other materials. Due to this non-uniform dispersion, not only the mechanical properties of the composite material composition, but also the flowability and moldability are reduced.

COOH-functionalized graphene nanoplates (GNP) are chemically bonded to a carboxyl group (-COOH) to general GNP, and since the carboxyl group of GNP is polar, it is easy to combine with a thermoplastic plastic having a polarity. to be evenly distributed. Therefore, COOH-functionalized GNP improves not only electrical conductivity but also mechanical properties, flowability, and moldability due to uniform dispersion in the composite material composition compared to general GNP. The COOH-functionalized GNP may be 3 to 6 wt%, and if it is less than 3 wt%, the effect of improving the electromagnetic wave shielding function according to the addition is insignificant, and if it exceeds 6 wt%, the dispersibility of the conductive filler in the composite material composition is lowered, so that the mechanical Physical properties, flowability, and moldability are deteriorated.

The composition of the present invention may further include various additives, such as antioxidants, lubricants, compatibilizers, colorants, release agents, flame retardants, plasticizers, antioxidants, and the like, and these may be used alone or in combination of two or more. The amount of the additive used can be appropriately adjusted according to the desired end use and properties. In an embodiment of the present invention, antioxidants were included in order to prevent thermal aging due to high temperature and to secure long-term heat resistance of the composite material composition in the injection process or extrusion process, and a lubricant was included to increase miscibility.

As raw materials of Examples of the present invention, the following were used.

1) PBT: BLUESTAR's PBT 1100

2) Carbon fiber: TR06Q from Mitsubishi Rayon (6 mm length chopped carbon fiber sized with epoxy resin)

3) Carbon black: Unipetrol's Chezacarb AC-80 (average particle diameter: 40 nm, nitrogen adsorption specific surface area 800 m ² /g)

4) COOH functionalized GNP: ADG-COOH from AD Nano Technologies (thickness: 2 to 5 nm, surface area: 250 m ² /g or less)

5) GNP: AD-GNP of AD Nano Technologies (thickness: 2 to 5 nm, surface area: 250 m ² /g or less)

6) Antioxidant: IRGANOX1010 from CIBA chemical

7) Lubricant: Shinwon Chemical's Hi-Lube

Results data of Examples of the present invention were evaluated and recorded based on the following.

1) Density: It was evaluated according to ASTM D792, and the unit is g/cm ² .

2) Tensile strength: It was evaluated according to ASTM D638 (5 mm/min condition), and the unit is MPa.

3) Electromagnetic wave shielding effect: Evaluated according to ASTM D4935 (frequency of 1 GHz condition), and the unit is dB.

4) Melt index: evaluated by ASTM D1238 (275°C/5kg condition), and the unit is g/10min.

5) Moldability: Qualitatively evaluated whether the extrusion or injection product was molded or not molded.

In order to evaluate the improved effect of the composition of the present invention, the following was reviewed.

PBT, carbon fiber, carbon black, COOH functionalized GNP, antioxidant, and lubricant were mixed in each of the following amounts. Specifically, a twin-screw extruder (L/D=44, Φ=32mm) was heated to 260°C. Thereafter, 75.2 wt% of PBT, 0.5 wt% of antioxidant, and 0.3 wt% of lubricant were added to the primary raw material inlet located at the front end of the extruder. Thereafter, 1.0 wt% of carbon black and 3.0 wt% of COOH-functionalized GNP were added to the secondary inlet located in the middle of the twin-screw extruder through a side feeder. Thereafter, 20.0 wt% of carbon fiber was added through a side feeder into the third inlet located at the end of the twin-screw extruder. A composite material composition was prepared by hot-melting and kneading the input material throughout the process. This was dried in a hot air dryer at 90° C. for 4 hours. Specimens for measurement and evaluation of the composition in the form of dried pellets were prepared at an injection temperature of 280°C using a 110t injection machine. After the specimen was left at 23° C. and 50% relative humidity for 48 hours, it was evaluated and recorded by the above method, and the results are shown in Table 1.

72.2% by weight of PBT, 0.5% by weight of antioxidant, 0.3% by weight of lubricant in the first raw material inlet, 1.0% by weight of carbon black, 6.0% by weight of COOH functionalized GNP in the second inlet, and carbon in the third inlet All were tested, evaluated, and recorded in the same manner except that 20.0 wt% of fiber was added.

70.2% by weight of PBT, 0.5% by weight of antioxidant, 0.3% by weight of lubricant in the primary raw material inlet, 1.0% by weight of carbon black, 3.0% by weight of COOH functionalized GNP in the secondary inlet, and carbon in the third inlet All were tested, evaluated, and recorded in the same manner except that 25.0 wt % of the fiber was added.

67.2% by weight of PBT, 0.5% by weight of antioxidant, 0.3% by weight of lubricant in the first raw material inlet, 1.0% by weight of carbon black, 6.0% by weight of COOH functionalized GNP in the second inlet, and carbon in the third inlet All were tested, evaluated, and recorded in the same manner except that 25.0 wt % of the fiber was added.

Meanwhile, in order to compare the improved effect of the composition of the present invention, the following was reviewed.

[ Comparative example 1 to 8]

PBT, carbon fiber, carbon black, COOH functionalized GNP, antioxidant, and lubricant were mixed in the respective amounts shown in Tables 2 and 3 below. Specifically, a twin-screw extruder (L/D=44, Φ=32mm) was heated to 260°C. Thereafter, 62.2 to 80.2 wt% of PBT, 0.5 wt% of antioxidant, and 0.3 wt% of lubricant were added to the primary raw material inlet located at the front end of the extruder. Thereafter, 1.0 wt% of carbon black and 0.0 to 9.0 wt% of COOH-functionalized GNP were added to the secondary inlet located in the middle of the twin-screw extruder through a side feeder. Thereafter, 15 to 30.0 wt % of carbon fiber was added through the side feeder to the third inlet located at the end of the twin screw extruder. A composite material composition was prepared by hot-melting and kneading the input material throughout the process. This was dried in a hot air dryer at 90° C. for 4 hours. Specimens for measurement and evaluation of the composition in the form of dried pellets were prepared at an injection temperature of 280°C using a 110t injection machine. This specimen was left for 48 hours at 23° C. and 50% relative humidity, and then evaluated and recorded by the above method, and the results are shown in Tables 2 and 3.

This is to compare and evaluate the cases in which the contents of PBT, COOH-functionalized GNP, and carbon fiber were changed, respectively, compared with Examples 1 to 4.

[ Comparative example 9]

75.2 wt% of PBT, 0.5 wt% of antioxidant, 0.3 wt% of lubricant in the first raw material inlet, 1.0 wt% of carbon black, 3.0 wt% of GNP in the second inlet, and 20.0 wt% of carbon fiber in the third inlet All tests, evaluations, and records were performed in the same manner except for the input, and the results are shown in Table 4.

This is to evaluate the case of inputting the same amount of general GNP instead of COOH-functionalized GNP as compared with Example 1.

Results data of the Examples and Comparative Examples are shown in Tables 1 to 4 below.

Component ratio (wt%) Example 1 Example 2 Example 3 Example 4 1. PBT 75.2 72.2 70.2 67.2 2. Carbon Fiber 20.0 20.0 25.0 25.0 3. Carbon Black 1.0 1.0 1.0 1.0 4. COOH-GNP 3.0 6.0 3.0 6.0 5. Antioxidants 0.5 0.5 0.5 0.5 6. Lubricant 0.3 0.3 0.3 0.3 result data Example 1 Example 2 Example 3 Example 4 1. Density 1.36 1.37 1.38 1.40 2. Tensile strength 144 141 159 154 3. Electromagnetic wave shielding rate 41 47 46 54 4. Melt index 30 19 20 11 5. Formability Good Good Good Good

Component ratio (wt%) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 1. PBT 78.2 69.2 73.2 64.2 2. Carbon Fiber 20.0 20.0 25.0 25.0 3. Carbon Black 1.0 1.0 1.0 1.0 4. COOH-GNP 0.0 9.0 0.0 9.0 5. Antioxidants 0.5 0.5 0.5 0.5 6. Lubricant 0.3 0.3 0.3 0.3 result data Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 1. Density 1.34 1.39 1.37 1.41 2. Tensile strength 148 135 163 150 3. Electromagnetic wave shielding rate 32 56 35 60 4. Melt index 40 7 31 2 5. Formability Good bad Good bad

Component ratio (wt%) Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 1. PBT 80.2 65.2 77.2 62.2 2. Carbon Fiber 15.0 30.0 15.0 30.0 3. Carbon Black 1.0 1.0 1.0 1.0 4. COOH-GNP 3.0 3.0 6.0 6.0 5. Antioxidants 0.5 0.5 0.5 0.5 6. Lubricant 0.3 0.3 0.3 0.3 result data Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 1. Density 1.33 1.41 1.35 1.42 2. Tensile strength 125 177 126 171 3. Electromagnetic wave shielding rate 37 52 43 58 4. Melt index 37 8 26 4 5. Formability Good bad Good bad

Component ratio (wt%) Comparative Example 9 1. PBT 75.2 2. Carbon Fiber 20.0 3. Carbon Black 1.0 4. GNP 3.0 5. Antioxidants 0.5 6. Lubricant 0.3 result data Comparative Example 9 1. Density 1.36 2. Tensile strength 135 3. Electromagnetic wave shielding rate 37 4. Melt index 19 5. Formability Good

In order to achieve the object of the present invention, the composition of the present invention has a density of 1.4 g/cm ² or less according to ASTM D792, a tensile strength of 140 MPa or more according to ASTM D638, and an electromagnetic wave shielding efficiency of 40 dB or more according to ASTM D4935, ASTM D1238 melt index of 10 g/10 min or more, and thus extrusion or injection moldability may be good.

Looking at the result data in Table 1, it can be seen that the composite material compositions of Examples 1 to 4 of the present invention satisfy all of the above requirements. That is, the composite material compositions of Examples 1 to 4 of the present invention have a lower density than metal, so they can be lightweight, and can obtain a high electromagnetic wave shielding effect at the metal level, and at the same time have excellent tensile strength (mechanical properties) and melt index. Because it is good, various types of extrusion or injection molding are possible, so the workability may be higher than that of metal. These results show that the purpose, configuration, and effect are remarkably different from Patent Document 1, which focuses only on enhancing the electromagnetic shielding effect, as well as the existing composite material for electromagnetic shielding for metal replacement.

Let's look at it in detail. In Example 4 of the present invention, the content of the conductive filler added to the thermoplastic is 32 wt%, which is 13 wt% lower than the 45 wt% disclosed as the best example of Patent Document 1, but the electromagnetic wave shielding effect is 54 dB, 55 dB is at almost the same level as However, the tensile strength is 154 MPa, which is almost twice as high as that of 82 MPa, and flowability and formability are also expected to be significantly high (taking into account the low flexural strength in Patent Document 1). It can be seen that it has a very high marketability than the example of In addition, in Comparative Example 4 of the present invention, when the conductive filler content is increased to 35% by weight (even though it is still a whopping 10% by weight compared to Patent Document 1), the electromagnetic wave shielding effect reaches 60 dB. It can be seen that rather outperform

In Examples 1 to 4 of the present invention, the content of the conductive filler added to the thermoplastic plastic is 24.0 to 32.0% by weight. And the content of the conductive filler added in Comparative Examples 1 to 9 of the present invention is 19.0 to 37.0 wt%. Specifically, it was examined whether the requirements of the composite material composition suitable for the present invention were satisfied by appropriately changing the carbon fiber or COOH-functionalized GNP content in the conductive filler.

First, if the content of carbon fiber in the composite material composition of the present invention is 30.0% by weight or more, the electromagnetic wave shielding effect is very high at 50 dB or more, whereas the melt index is less than 10 g/10min and the moldability is poor, so the marketability is low. On the other hand, when the carbon fiber content is 15.0 wt% or less, it can be seen that the melt index is high and the moldability is good, but the electromagnetic wave shielding effect and the tensile strength level are not high (Comparative Examples 5 to 8). Therefore, it can be derived that the appropriate range of the carbon fiber content in the composite material composition of the present invention is 20.0 to 25.0 wt%.

Next, when the content of COOH-functionalized GNP in the composite material composition of the present invention is 9.0% by weight or more, the electromagnetic wave shielding effect is very high as 50 dB or more, while the melt index is less than 10 g/10min and the moldability is poor, so it is also marketable this is low On the other hand, when the content of the COOH-functionalized GNP is 0.0 wt%, it can be seen that the melt index is high and the moldability is good, but the level of the electromagnetic wave shielding effect is not high (Comparative Examples 1 to 4). Therefore, it can be derived that the appropriate range of the content of the COOH functionalized GNP in the composite material composition of the present invention is 3.0 to 6.0% by weight.

In addition, it can be seen that the tensile strength, the electromagnetic wave shielding effect, and the melt index were all lowered when the same amount of general GNP was added instead of the COOH-functionalized GNP in the composite material composition of the present invention (Comparative Example 9). The reason is that when using general GNPs, it is difficult to disperse them in thermoplastics due to the van der Waals force and stable structure between them. When using COOH-functionalized GNPs, polar carboxyl groups are combined in the thermoplastic. This is because it induces even dispersion. Therefore, in order to achieve the object of the present invention, it is preferable to use a COOH-functionalized GNP that can achieve high mechanical properties (tensile strength), electromagnetic wave shielding effect, flowability and moldability (melt index) compared to general GNP.

In the present invention, COOH-functionalized GNP was used in particular to maximize the electromagnetic wave shielding function of the conductive filler added in the thermoplastic plastic to achieve an effect equal to or greater than that of other materials with a smaller content. The present invention minimizes deterioration of mechanical properties by adding a small amount of conductive filler compared to Patent Document 1 to achieve an equivalent electromagnetic wave shielding effect, and improves flowability and moldability during product manufacturing. In addition, the present invention discloses a composition having a higher electromagnetic wave shielding function than the best composite material composition disclosed in Patent Document 1, and the composition is still the same content as in Patent Document 1 as a conductive filler added in a small amount compared to Patent Document 1 It also shows that a much higher electromagnetic wave shielding function can be achieved when applying a conductive filler of

Although the present invention has been described in detail through representative embodiments above, those of ordinary skill in the art to which the present invention pertains will understand that various modifications are possible within the limits without departing from the scope of the present invention with respect to the above embodiments. . Therefore, the scope of the present invention should not be limited to the above embodiments, but should be defined by all changes or modifications derived from the following claims, claims and equivalent concepts.

Claims (6)

In the composite material composition having an electromagnetic wave shielding function,
67.2 to 75.2 weight percent of thermoplastic; and
24.0 to 32.0% by weight of a conductive filler;
The conductive filler includes a COOH functionalized graphene nanoplate (GNP), wherein the COOH functionalized graphene nanoplate (GNP) is 3.0 to 6.0 wt% of the total composite material composition,
Composite material composition with electromagnetic wave shielding function
The method of claim 1,
The conductive filler includes carbon fiber, wherein the carbon fiber is 20.0 to 25.0 wt% of the total composite material composition, characterized in that the composite material composition having an electromagnetic wave shielding function.
delete The method of claim 1,
The thermoplastic plastic is polybutylene terephthalate (PBT), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), polyamide (PA), polycarbonate (PC), modified polyphenylene oxide (MPPO), A composite material composition having an electromagnetic wave shielding function that is selected from the group consisting of polyphenylene sulfide (PPS), or a mixture thereof.
delete A molded article manufactured including the composite material composition having the electromagnetic wave shielding function of any one of claims 1, 2, and 4.

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