KR101425975B1 - Polymer resin blend composition for automotive exterior, article for automotive exterior and preparing method of the same - Google Patents

Abstract

The present invention relates to a polymer resin blend composition for preparing automotive exterior materials, a resin molded product for the automotive exterior materials, and a preparation method thereof, comprising a first polymer resin including a polyethylene-polypropylene copolymer and a graphene; a second polymer resin including the polyethylene-polypropylene copolymer and a long fiber reinforced material impregnated to the polyethylene-polypropylene copolymer.

Description

TECHNICAL FIELD [0001] The present invention relates to a polymer resin blend composition for manufacturing an automotive exterior material, a resin molded article for automobile exterior materials, and a method for manufacturing the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a polymer resin blend composition for use in the manufacture of automobile exterior materials, a resin molded article for automotive exterior materials, and a method of manufacturing the same. More specifically, the present invention can provide a resin composition having high flexural strength and tensile strength at low specific gravity, A polymer resin blend composition, a resin molded article for automotive exterior materials, and a method for producing the same.

The polypropylene resin has various characteristics such as excellent moldability, mechanical properties, and chemical resistance, and is widely used in fields such as automobile interior parts, home appliance parts, industrial materials, textile fields, and films. However, since such a polypropylene resin has a relatively low tensile strength and flexural strength, its use is restricted in areas requiring toughness and rigidity, such as automobile parts.

In order to improve the tensile strength, bending strength and impact strength of the polypropylene resin, methods of adding rigid stiffeners such as other polymer resins and rubber components have been used. However, the conventional reinforcing materials do not sufficiently improve the mechanical properties of the resin, and the comparatively expensive compatibilizer is essentially used to uniformly mix the resin with the polypropylene resin, so that economical efficiency can not be sufficiently secured.

In recent years, glass fibers have been widely used as rigid reinforcing materials in order to apply polypropylene resin to automobile parts and electric / electronic parts. The glass fiber is applied to various fields because it can obtain a property improvement effect even if it is used in a small amount compared to talc or whisker which has been used before, , The glass fiber is oriented in the resin flow direction (MD), so that the shrinkage ratio in the MD direction and the TD direction in the final product are different from each other, and warpage phenomenon (warpage or warpage) have.

Accordingly, it is possible to minimize the use of an additional compatibilizing agent and to maintain or improve the toughness and stiffness to a certain level or higher, and to provide a polymer resin for manufacturing automotive exterior materials having excellent processability and conductivity Blend compositions, and resin molded articles for automobile exterior materials.

The present invention is to provide a polymer resin blend composition for automobile exterior materials which can realize high flexural strength and tensile strength even at a low specific gravity and exhibit high conductivity.

It is another object of the present invention to provide a resin molded article for automobile exterior materials which can realize a high flexural strength and tensile strength even at a low specific gravity and exhibit high conductivity.

In addition to this, the present invention provides a method for producing the resin molded article for automobile exterior materials.

The present invention relates to a first polymer resin comprising a polyethylene-polypropylene copolymer and a graphene having a melt index (ASTM D-1238, 230 DEG C) of 50 to 70 g / 10 min; And a second polymeric resin comprising a polyethylene-polypropylene copolymer having a melt index (ASTM D-1238, 230 占 폚) of 50 to 70 g / 10 min and a long-fiber reinforcement impregnated in the polyethylene-polypropylene copolymer , And a polymer resin blend composition for manufacturing an automotive exterior material.

The present invention also provides a resin molded article for automobile exterior materials comprising the polymer resin blend composition for manufacturing the automobile exterior material.

In addition, the present invention provides a method for producing the resin molded article for automobile exterior materials.

Hereinafter, the polymer resin blend composition for automobile exterior materials according to the specific embodiment of the present invention, the resin molded article for automobile exterior materials and the method for manufacturing the same will be described in detail.

In the present specification, the first and second expressions are used to clearly distinguish the polymer resin, and the order of the reaction or other inventive features is not limited to the first and second terms.

According to an embodiment of the present invention, there is provided a thermoplastic resin composition comprising: a first polymer resin including a polyethylene-polypropylene copolymer and a graphene having a melt index (ASTM D-1238, 230 DEG C) of 50 to 70 g / 10 min; And a second polymeric resin comprising a polyethylene-polypropylene copolymer having a melt index (ASTM D-1238, 230 占 폚) of 50 to 70 g / 10 min and a long-fiber reinforcement impregnated in the polyethylene-polypropylene copolymer , A polymer resin blend composition for manufacturing an automotive exterior material may be provided.

The present inventors have found that a first polymer resin comprising a polyethylene-polypropylene copolymer having a specific melt index and graphene, a second polymer resin comprising a polyethylene-polypropylene copolymer having a specific melt index and a long fiber reinforcement It is possible to maintain or improve the physical properties such as tensile strength, flexural strength, and conductivity of the polymeric resin blend composition for automobile exterior materials manufactured by blending, while exhibiting a low specific gravity, as well as warpage And the appearance characteristics can be improved by minimizing the development (warping or warping).

Particularly, the polymer resin blend composition for automobile exterior materials is produced by mixing a graphene and a long fiber reinforced material with a polyethylene-polypropylene copolymer to prepare a polymer resin and blending the same, thereby obtaining a polyethylene-polypropylene copolymer, a long fiber reinforcing material and a Graphene Can be increased and the physical properties such as tensile strength and elasticity of the resin composition can be improved. Further, as described later, the polymer resin blend composition for manufacturing an automobile exterior material can improve the conductivity by lowering the surface resistance particularly including Graphene.

The polyethylene-polypropylene copolymer in the first polymer resin and the second polymer resin of the polymer resin blend composition for producing automotive exterior materials may exhibit a melt index (ASTM D-1238, 230 ° C) of 50 to 70 g / 10 min. The polyethylene-polypropylene copolymer may be used without limitation, for example, an ethylene-propylene block copolymer, an ethylene-propylene random copolymer, or the like, which is known to be commonly used in long fiber- But it is preferable to use a polyethylene-polypropylene copolymer having a melt index of 50 to 70 g / 10 min (ASTM D1238, 230 DEG C).

If the melt index of the polyethylene-polypropylene copolymer is less than 50 g / 10 min (ASTM D1238, 230 ° C), it may be difficult to obtain sufficient processability in the molding process and the high viscosity may interfere with the dispersion of the long fiber reinforcement material and Graphene . If the melt index of the polyethylene-polypropylene copolymer exceeds 70 g / 10 min (ASTM D1238, 230 DEG C), the final product may not have adequate impact strength due to the low viscosity, and the tensile and flexural strength and elastic modulus Which may cause deterioration.

Also, the polyethylene-polypropylene copolymer may contain 5 to 15% by weight of ethylene; And a residual amount of polypropylene. If the content of ethylene in the copolymer is less than 5% by weight, the impact strength may be lowered, and if it is more than 15% by weight, the flexural strength and flexural modulus may decrease.

The first polymer resin of the polymer resin blend composition for manufacturing an automobile exterior material of one embodiment may include 0.1 to 10% by weight of graphene and a residual amount of a polyethylene-polypropylene copolymer.

The Graphene (graphene) is composed of carbon having high chemical stability, and is superior in conductivity to silicon used in semiconductors, and has remarkably strong mechanical strength than steel, so that the conductivity and mechanical properties of the resin composition can be improved. The Graphene exhibits a nano-sized two-dimensional planar shape and can be more easily impregnated into the polyethylene-polypropylene copolymer in a uniform form.

The first polymer resin may contain 0.1 to 20% by weight, preferably 1 to 10% by weight of Graphene. If the content of Graphene is too small, the degree of improvement of conductivity may be insignificant. If the content of Graphene is too large, the Graphene may not be uniformly dispersed and the physical properties may be deteriorated.

In addition, the second polymer resin of the polymer resin blend composition for manufacturing an automobile exterior material of one embodiment comprises 1 to 60% by weight of long fiber reinforcement; And a residual amount of a polyethylene-polypropylene copolymer.

The long fiber reinforcing material is added in order to improve the mechanical properties of the resin composition. If the long fiber reinforcing material is contained in too small amount, the degree of improvement of the mechanical properties of the polymer resin blend composition and resin molded product If the content of the long fiber reinforcement is too large, the impregnation with the polyethylene-polypropylene copolymer becomes incomplete, and the appearance performance may be rapidly deteriorated.

Examples of the long fiber reinforcing material used for the second polymer resin include glass fiber filaments, carbon fiber filaments, graphite fiber filaments, metal fiber filaments, aramid fiber filaments, polyethylene filament filaments, PAN (polyacrylonitrile) filament filaments, (Poly Ether Ether Ketone) fiber filament, or a mixture thereof.

Particularly, among the filaments, the carbon fiber filament has characteristics of high strength and high rigidity. The second polymer resin containing the same exhibits excellent mechanical properties with a low specific gravity. Thus, the polymer resin blend composition for manufacturing automobile exterior materials and the automobile exterior material And the physical properties such as tensile strength, flexural strength and flexural modulus can be improved.

The carbon fiber filament is a fiber obtained by carbonizing and crystallizing an organic fiber by heat treatment at an appropriate temperature in an inert gas. The second polymer resin of the embodiment may use carbon fibers known to be used in the art without limitation, For example, it may be obtained by firing polyacryonitrile (PAN) fibers or pitch fibers at 1000 to 3000 占 폚.

An epoxy resin, a polyester resin, a polyurethane resin, or a mixture thereof may be bonded to the surface of the carbon fiber filament. Since the carbon fibers contain carbon as a main component, they may have low reactivity and adhesiveness with other polymers.

The long fiber reinforcement material may have a length of 2 mm or more, and more preferably 2 mm to 13 mm. The long fiber reinforcing material may serve to improve the mechanical properties of the automobile exterior material which is finally contained in the resin composition in a state of being impregnated with polyethylene-polypropylene in the second polymer resin. , The above-described characteristics may not be sufficiently expressed.

On the other hand, such a second polymer resin can be prepared by loosening a bundle of fibers from the filaments of the long fiber reinforcement material, and then impregnating and / or coating and adhering the polyolefin resin into the fiber filaments. For example, the fiber bundle may be simply heated while adhering a powdered suspension of a modified or normal polyolefin resin to the filament, or the fiber bundle may be impregnated by contacting the molten resin by heating, And then impregnating the polyolefin powder with heat and melting.

The second polymer resin produced by the above-mentioned method may have a length of 3 mm to 500 mm. If the length of the polymer resin is too short, the mechanical properties may be deteriorated. If the length is too long, there is a limit to the difficulty of charging the raw material during the secondary molding.

The at least one polymer resin selected from the group consisting of the first polymer resin and the second polymer resin may further comprise 1 to 10% by weight of a polypropylene grafted with a dicarboxylic acid or an acid anhydride thereof.

The 'dicarboxylic acid or its anhydride-grafted polypropylene' refers to a polymer formed by branching a dicarboxylic acid or an acid anhydride thereof to the main chain of polypropylene to form a branched chain. Specific examples of the dicarboxylic acid For example, maleic acid, phthalic acid, itaconic acid, citraconic acid, alkenylsuccinic acid, cis-1,2,3,6 tetrahydrophthalic acid, 4-methyl-1,2,3,6-tetrahydrophthalic acid or a mixture of two or more thereof , And the acid anhydride of the dicarboxylic acid may be a dicarboxylic acid anhydride of the above-mentioned examples. The polypropylene in which the dicarboxylic acid or an acid anhydride thereof is grafted is optimally contained in each polymer resin or one kind of polymer resin in order to improve the compatibility between the polyethylene-polypropylene copolymer and the graphene and long fiber reinforcement. , And more preferably maleic anhydride grafted polypropylene.

The polypropylene grafted with the dicarboxylic acid or an acid anhydride thereof may be polypropylene having a graft ratio of 1.0 to 3.0% by weight of the dicarboxylic acid or an acid anhydride thereof.

The first polymer resin and the second polymer resin may be contained in a weight ratio of 1: 1 to 1: 3, and preferably in a weight ratio of 1: 1 to 1: 2 in the polymer resin blend composition for outer cover material production.

If the content of the first polymer resin is too small as compared with that of the second polymer resin, the flowability of the resin composition may be lowered, resulting in a problem in the production of the resin molded article. If the content of the first polymer resin is too large as compared with that of the second polymer resin, the content of the long fiber reinforcement may be insufficient and the mechanical properties of the final product may be deteriorated.

Meanwhile, the first polymer resin and the second polymer resin may form a crosslink in the polymer resin blend composition for manufacturing an automobile exterior material according to one embodiment. Specifically, the long fiber reinforcing material and the Graphene may be uniformly impregnated into the polyethylene-polypropylene copolymer, respectively, and the first polymer resin and the second polymer resin including the same may be in a crosslinked state. The polymer resin blend composition for manufacturing automotive exterior materials can exhibit high strength and high conductivity by including polymer resins having such bonding state.

The polymer resin blend composition for manufacturing an automobile exterior material may further comprise 0.1 to 10% by weight of one or more auxiliary agents selected from the group consisting of compatibilizers, antioxidants, mold release agents, antistatic agents and lubricants.

The auxiliary agent is an ordinary resin additive suitably used according to a desired use, such as improving the processability and functionality of the resin, without interfering with the affinity between the polyolefin-based binder resin and the long-fiber reinforcement, Release agents, antistatic agents, lubricants, and the like. If the amount of the auxiliary agent used is too small, the effect of adding the auxiliary agent can not be sufficiently obtained. If the amount of the auxiliary agent used is too large, the physical properties of the resin such as strength may be lowered.

The polymer resin blend composition for manufacturing an automobile exterior material of this embodiment may have a surface resistance of 10 ³ Ω / sq or less. As described above, the resin composition can improve the compatibility with the second polymer resin including the long fiber reinforcing material by containing Graphene as a polymer resin impregnated with polyethylene-polypropylene copolymer at a specific ratio, It can have a lower surface resistance than that of the conventional polymer resin blend composition for manufacturing an automobile exterior material, and thus can exhibit high conductivity.

The polymeric resin blend composition for manufacturing an automobile exterior material may have a specific gravity of 1.1 g / cm3 or less, preferably 1.05 g / cm3 or less, and may have a relatively low specific gravity and a high tensile strength, for example, 800 Kgf / Cm2, a flexural strength of 1,000 Kgf / cm2 or more, and a flexural modulus of 90,000 Kgf / cm2 or more.

According to another embodiment of the present invention, there is provided a thermoplastic resin composition comprising: a first polymer resin including a polyethylene-polypropylene copolymer and a graphene having a melt index (ASTM D-1238, 230 DEG C) of 50 to 70 g / 10 min; And a second polymeric resin comprising a polyethylene-polypropylene copolymer having a melt index (ASTM D-1238, 230 占 폚) of 50 to 70 g / 10 min and a long-fiber reinforcement impregnated in the polyethylene-polypropylene copolymer A resin molded article for an automobile exterior material can be provided.

As described above, the inventors of the present invention have found that a polypropylene resin composition comprising a first polymer resin comprising a polyethylene-polypropylene copolymer and a graphene having a specific melt index, a polyethylene-polypropylene copolymer having a specific melt index and a second The polymer resin blend composition for automobile exterior material manufactured by blending the polymer resin exhibits a low specific gravity and can maintain or improve the physical properties such as tensile strength, flexural strength and conductivity at a certain level or more, It can be used as an automobile exterior material because of its excellent appearance characteristics. Especially, it is confirmed that it is suitable for use as an automobile fender, and the invention is completed through experiments.

The above contents regarding the polyethylene-polypropylene copolymer, the long fiber reinforcing material, Graphene, and the like can be applied in connection with the polymer resin blend composition for manufacturing automotive exterior materials of one embodiment of the present invention.

The resin molded article for an automobile exterior material of this embodiment may have a specific gravity of 1.1 g / cm 3 or less and a surface resistance of 10 ³ Ω / sq or less. Resin molded articles for automobile exterior materials having specific gravity and surface resistance in the above range have lower specific gravity and lower surface resistance than steel materials conventionally used for automobile exterior materials, and thus can exhibit excellent workability and conductivity.

Meanwhile, the resin molded article for automobile exterior material may include a crosslinking reaction product of the first polymer resin and the second polymer resin. Specifically, the long fiber reinforcing material and the Graphene may be uniformly impregnated into the polyethylene-polypropylene copolymer, and the first polymer resin and the second polymer resin including the same may be crosslinked through the molding step. The resin molded article for an automobile exterior material of one embodiment can exhibit the effect of high strength and high conductivity by including the polymer resin having such a bonding state.

Such resin molded articles for automobile exterior materials can be specifically used for automobile fenders, tail gates, hoods, electronic parts, and the like.

According to another embodiment of the present invention, there is also provided a method of producing a thermoplastic resin composition comprising a first polymer resin comprising a polyethylene-polypropylene copolymer and a graphene having a melt index (ASTM D-1238, 230 DEG C) of 50 to 70 g / , A polyethylene-polypropylene copolymer having a melt index (ASTM D-1238, 230 DEG C) of 50 to 70 g / 10 min and a long-fiber reinforcement impregnated in the polyethylene-polypropylene copolymer, A method of manufacturing a resin molded article for automobile exterior materials, comprising a step of molding by a method selected from the group consisting of compression molding, extrusion molding, extrusion compression molding, low pressure injection molding, gas injection molding, foam injection molding and foam extrusion molding Can be provided.

As described above, the inventors of the present invention have found that a polypropylene resin composition comprising a first polymer resin comprising a polyethylene-polypropylene copolymer and a graphene having a specific melt index, a polyethylene-polypropylene copolymer having a specific melt index and a second The polymeric resin blend composition for manufacturing an automobile exterior material manufactured by blending a polymer resin exhibits a low specific gravity and can maintain or improve physical properties such as tensile strength, flexural strength and conductivity at a certain level or more, It is confirmed that the molded product which is finally manufactured has excellent appearance and can be used as an automobile exterior material. Especially, it is confirmed that it is suitable for use as an automobile fender, and completed the invention.

The above contents regarding the polyethylene-polypropylene copolymer, the long fiber reinforcing material, Graphene, and the like can be applied in connection with the polymer resin blend composition for manufacturing automotive exterior materials of one embodiment of the present invention.

According to the present invention, it is possible to provide a polymer resin blend composition for automobile exterior material manufacturing, a molded resin product for automobile exterior materials, and a method of manufacturing the same, which can realize high flexural strength and tensile strength even at low specific gravity.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

< Example  And Comparative Example : Polymer resin for automobile exterior material Blend  Preparation of composition &gt;

Example 1

(1) Production of first polymer resin

A first polymer comprising 98% by weight of a polyethylene-polypropylene copolymer (melt index: 60 g / 10 min) containing 8% by weight of polyethylene and the remainder of polypropylene and 2% by weight of graphene and having a length of 11 mm The resin was prepared using a twin screw extruder apparatus with a screw diameter of 40 mm at a temperature of 230 캜.

(2) Production of second polymer resin

55% by weight of a polyethylene-polypropylene copolymer (melt index: 60 g / 10 min) containing 8% by weight of polyethylene and the remaining amount of polypropylene, 5% by weight of polypropylene having 2.2% by weight of maleic anhydride grafted, (11 mm in length) and having a length of 11 mm was impregnated with a carbon fiber through an impregnation die using a twin screw extruder apparatus having a screw diameter of 40 mm at a temperature of 230 ° C.

(3) Polymer resin for automobile exterior materials Blend  Preparation of composition

The first polymer resin and the second polymer resin were hand-mixed at a weight ratio of 1: 1 to prepare a polymer resin blend composition for automobile exterior materials.

Comparative Example 1

A resin composition was prepared in the same manner as in Example 1, except that a polypropylene homopolymer (melt index: 34 g / 10 min) was used instead of the polyethylene-polypropylene copolymer and Graphene was not used.

Comparative Example  2

A resin composition was prepared in the same manner as in Example 1, except that a polypropylene homopolymer (melt index: 34 g / 10 min) was used instead of the polyethylene-polypropylene copolymer and Graphite was used instead of Graphene .

Comparative Example  3

A resin composition was prepared in the same manner as in Example 1, except that a polypropylene homopolymer (melt index: 34 g / 10 min) was used instead of the polyethylene-polypropylene copolymer and CNT was used instead of Graphene .

< Experimental Example : Evaluation of physical properties of resin>

Experimental Example 1 . Tensile strength measurement

The tensile strengths of the injection molded test pieces of the resin compositions obtained in the above Examples and Comparative Examples were measured using a WL2100 (WITHLAB Co., Ltd., Korea) apparatus based on the criteria of ASTM D638.

Experimental Example 2 . Bending strength  Measure

Flexural strengths of injection molded test pieces of the resin compositions obtained in the above Examples and Comparative Examples were measured using a WL2100 (WITHLAB Co., Ltd., Korea) apparatus based on the criteria of ASTM D790.

Experimental Example 3 . Flexural modulus  Measure

Flexural modulus of each injection molded test piece of the resin composition obtained in the above Examples and Comparative Examples was measured using a WL2100 (WITHLAB Co., Ltd., Korea) apparatus based on the criteria of ASTM D790.

Experimental Example 4 . Measurement of surface resistance

Using Loresta-EP MCP-T360 apparatus, surface resistances of injection molded test pieces of the resin compositions obtained in the above Examples and Comparative Examples were measured based on 2T plate specimens.

Experimental Example 5 . Measurement of specific gravity

The specific gravity of each injection molded test piece of the resin composition obtained in the above Examples and Comparative Examples was measured using MD-300S (MIRAGE, Japan) apparatus based on the criteria of ASTM D 792.

The results of Experimental Examples 1 to 5 are shown in Table 1 below.

importance The tensile strength Flexural strength Flexural modulus Surface resistance unit (Kgf / cm2) (Kgf / cm2) (Kgf / cm2) (Ω / sq) Example 1 1.01 955 1120 90334 10 ² Comparative Example 1 1.01 790 890 89284 10 ⁵ Comparative Example 2 1.01 850 930 88225 10 ⁴ Comparative Example 3 1.01 855 960 89885 10 ³

As shown in Table 1, the polymer resin blend composition for manufacturing automotive exterior materials of the present invention has a high specific gravity and a sufficient tensile strength, and can not only greatly improve the elasticity of the product, but also, due to the use of Graphene It has been confirmed that the surface resistance is lowered to exhibit high conductivity.

On the other hand, in Comparative Examples 1 to 3 using Graphite or CNT, a polypropylene homopolymer was used in place of the polyethylene-polypropylene copolymer, the surface resistance was significantly higher than that in Examples, and the conductivity was low and the tensile strength and the flexural strength And the like were also found to be relatively low.

Claims (18)

A first polymer resin comprising a polyethylene-polypropylene copolymer and a graphene having a melt index (ASTM D-1238, 230 占 폚) of 50 to 70 g / 10 minutes; And
And a second polymer resin comprising a polyethylene-polypropylene copolymer having a melt index (ASTM D-1238, 230 DEG C) of 50 to 70 g / 10 minutes and a long- Polymer resin blend composition for manufacturing automotive exterior materials.
The method according to claim 1,
Wherein the polyethylene-polypropylene copolymer of the first polymer resin and the second polymer resin comprises 5 to 15% by weight of ethylene; And a remaining amount of polypropylene.
The method according to claim 1,
Wherein the first polymer resin comprises 0.1-20% by weight of graphene and the balance polyethylene-polypropylene copolymer.
The method according to claim 1,
The second polymeric resin comprises from 1 to 60% by weight of a long fiber reinforcement; And a residual amount of a polyethylene-polypropylene copolymer.
The method according to claim 1,
The long fiber reinforcing material is selected from the group consisting of glass fiber filaments, carbon fiber filaments, graphite fiber filaments, metal fiber filaments, aramid fiber filaments, polyethylene filament filaments, PAN filament filaments, arylate fiber filaments, PEEK fiber filaments, By weight based on the weight of the polymer resin.
The method according to claim 1,
Wherein the long fiber reinforcement has a length of 2 mm or more.
The method according to claim 1,
Wherein the second polymer resin has a length of 3 mm to 500 mm.
The method according to claim 1,
Wherein the at least one polymer resin selected from the group consisting of the first polymer resin and the second polymer resin further comprises 1 to 10% by weight of a polypropylene grafted with a dicarboxylic acid or an acid anhydride thereof, Composition.
The method according to claim 1,
Wherein the first polymer resin and the second polymer resin are contained in a weight ratio of 1: 1 to 1: 3.
The method according to claim 1,
Wherein the first polymer resin and the second polymer resin form cross-linking.
The method according to claim 1,
And 0.1 to 10% by weight of at least one auxiliary agent selected from the group consisting of a compatibilizing agent, an antioxidant, a releasing agent, an antistatic agent and a lubricant.
The method according to claim 1,
And a surface resistance of 10 ³ Ω / sq or less.
The method according to claim 1,
And a specific gravity of 1.1 g / cm &lt; 3 &gt; or less.
A first polymer resin comprising a polyethylene-polypropylene copolymer and a graphene having a melt index (ASTM D-1238, 230 占 폚) of 50 to 70 g / 10 minutes; And
And a second polymer resin comprising a polyethylene-polypropylene copolymer having a melt index (ASTM D-1238, 230 DEG C) of 50 to 70 g / 10 minutes and a long- Resin Molded Products for Automotive Exterior Materials.
15. The method of claim 14,
1.1 g / ㎤ weight and 10 ³ Ω / sq having a surface resistance of less than, the resin molded article for automobile exterior or less.
15. The method of claim 14,
And a crosslinking reaction product of the first polymer resin and the second polymer resin.
15. The method of claim 14,
Wherein the resin molded article for automobile exterior materials is selected from the group consisting of automobile fenders, tail gates, hoods, and electronic parts.
A first polymer resin including a polyethylene-polypropylene copolymer and graphene having a melt index (ASTM D-1238, 230 DEG C) of 50 to 70 g / 10 minutes,
A second polymer resin including a polyethylene-polypropylene copolymer having a melt index (ASTM D-1238, 230 占 폚) of 50 to 70 g / 10 minutes and a long-fiber reinforcement impregnated in the polyethylene-polypropylene copolymer, Wherein the step of forming the molded article is carried out by a method selected from the group consisting of compression molding, extrusion molding, extrusion compression molding, low pressure injection molding, gas injection molding, foam injection molding and foam extrusion molding.