Conductive resin composition, its manufacturing method and molded article containing same

Abstract

The present invention relates to a conductive resin composition, a manufacturing method thereof, and a molded article including the same. According to the present invention, since the conductive resin composition has excellent moisture stability and heat resistance as well as excellent appearance, rigidity, and conductivity, the influence of moisture and heat due to exposure to the external environment is minimized. Therefore, the present invention has an effect of providing a conductive resin composition, a manufacturing method thereof, and a molded article including the same, which are particularly useful for applications as metal replacement exterior parts of automobiles.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0106747, filed on August 25, 2022, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a conductive resin composition, a manufacturing method thereof, and a molded article including the same. More particularly, the present invention relates to a conductive resin composition that has excellent moisture stability and heat resistance as well as excellent appearance, rigidity, and conductivity, thereby minimizing the effects of moisture and heat due to exposure to the external environment, and is therefore particularly useful for use in automotive exterior parts as an alternative to metal, a manufacturing method thereof, and a molded article including the same. [Background technology]

[0003] Recently, many studies have been conducted to resinify automobile exterior parts in order to improve automobile fuel efficiency, and blend resins of polyphenylene ether and polyamide in particular are widely used as materials for automobile exterior parts.

[0004] The blend resin is an attempt to combine the excellent heat resistance and impact resistance of polyphenylene ether with the excellent solvent resistance of polyamide, but there is a problem in that the compatibility is reduced and sufficient heat resistance is not exhibited.

[0005] Automotive exterior parts typically require painting, and electrostatic painting is often used to reduce total volatile organic compounds (TVOCs) and ensure high-quality appearance from an environmental perspective. To facilitate electrostatic painting, attempts have been made to impart conductivity by adding conductive materials such as carbon fiber and carbon black to blended resins. However, the addition of conductive materials can lead to problems such as a decrease in appearance quality and impact resistance.

[0006] US Pat. No. 6,352,654 discloses a conductive resin composition in which conductive carbon black is mixed with a polyphenylene ether-polyamide blend resin, which improves the adhesion and ductility of paint to the blend resin.

[0007] However, such blend resins have problems such as limited heat resistance, poor appearance due to pinholes on the surface when produced into molded products, and poor mechanical properties and dimensional stability due to moisture.

[0008] Therefore, there is an urgent need to develop a conductive resin composition that is applicable to automotive exterior parts and that has excellent appearance, mechanical properties, and conductivity, and is not affected by moisture and heat when exposed to the external environment. Summary of the Invention [Problem to be solved by the invention]

[0009] In order to solve the above-mentioned problems of the prior art, the present invention aims to provide a conductive resin composition that has excellent moisture stability and heat resistance as well as excellent appearance, rigidity, and conductivity, thereby minimizing the effects of moisture and heat due to exposure to the external environment, and is therefore particularly advantageous for use in automotive exterior parts that replace metal, and a method for manufacturing the same.

[0010] Another object of the present invention is to provide a molded article using the conductive resin composition for use as a substitute for metal exterior parts of automobiles.

[0011] The above and other objects of the present invention can all be achieved by the present invention described below. [Means for solving the problem]

[0012] In order to achieve the above object, the present invention provides: (A) 100 parts by weight of a base resin comprising a first polyester and a polyarylene ether; (B) 8 to 20 parts by weight of two or more first additives selected from a first polar polyolefin resin, a block copolymer impact modifier, and a polyfunctional reactant; (C) 4 to 14 parts by weight of three or more second additives selected from a second polar polyolefin resin, a second polyester, carbon nanotubes, and carbon nanoplates; A sea-island structure is provided that provides a continuous phase (sea), a dispersed phase (island), and an additional dispersed phase (sub-island), the continuous phase (Sea) is composed of the first polyester in the (A) base resin, the first polar polyolefin resin and the polyfunctional reactant in the (B) first additive, and the second polar polyolefin resin in the (C) second additive; the dispersed phase (islands) are constituted by the polyarylene ether in the (A) base resin, The additional dispersed phase (Sub Island) is composed of the block copolymer impact modifier in the (B) first additive and the carbon nanotubes and carbon nanoplates in the (C) second additive, thereby providing a conductive resin composition.

[0013] The present invention also provides 100 parts by weight of a base resin containing polyester and polyarylene ether; 1 to 20 parts by weight of a block copolymer impact modifier; 1 to 20 parts by weight of a multifunctional reactant; and 0.1 to 10 parts by weight of one or more selected from carbon nanotubes and carbon nanoplates; 8 The present invention provides a conductive resin composition having a resistance of ohm / sq or less.

[0014] The present invention also provides (A) 100 parts by weight of a base resin comprising a first polyester and a polyarylene ether; (B) 8 to 20 parts by weight of two or more first additives selected from a first polar polyolefin resin, a block copolymer impact modifier, and a polyfunctional reactant; (C) 4 to 14 parts by weight of three or more second additives selected from a second polar polyolefin resin, a second polyester, carbon nanotubes, and carbon nanoplates; and kneading and extruding the mixture using an extruder having nine or more kneading blocks to provide a continuous phase (Sea), a dispersed phase (Island), and a sea-island structure (Sea and Island) that provides an additional dispersed phase (Sub Island) within the continuous phase, the continuous phase (Sea) is composed of the first polyester in the (A) base resin, the first polar polyolefin resin and the polyfunctional reactant in the (B) first additive, and the second polar polyolefin resin in the (C) second additive; the dispersed phase (islands) are constituted by the polyarylene ether in the (A) base resin, The additional dispersed phase (Sub Island) is composed of the block copolymer impact modifier in the first additive (B) and the carbon nanotubes and carbon nanoplates in the second additive (C).

[0015] The present invention also provides a molded article comprising the conductive resin composition. [Effects of the Invention]

[0016] According to the present invention, there is provided a conductive resin composition having excellent moisture stability and heat resistance as well as excellent appearance, rigidity, and conductivity, thereby minimizing the effects of moisture and heat due to exposure to the external environment, and thus, particularly useful for use in automotive exterior parts as an alternative to metal, and a method for manufacturing the same.

[0017] Furthermore, molded articles made from the composition have excellent dimensional stability even when exposed to moisture, minimizing dimensional changes caused by exposure to the external environment.

[0018] Therefore, the conductive resin composition and molded article according to the present invention can be applied to the field of automotive exterior parts that require replacement of metal, including exterior panels, doors, fuel inlets, charging ports, etc. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram of an extruder equipped with nine or more kneading blocks, used for producing the conductive resin composition of the present invention. [Figure 2] This is a diagram showing the sea-island structure provided in Example 1 below. The sea-island structure is composed of a continuous phase (Sea), a dispersed phase (Island), and an additional dispersed phase (Sub-Island) formed inside the dispersed phase (Island). BEST MODE FOR CARRYING OUT THE INVENTION

[0020] The conductive resin composition of the present invention, its production method, and molded articles containing the same will be described in detail below.

[0021] The present inventors have confirmed that when a conductive resin composition is prepared by mixing a base resin including a first polyester and a polyarylene ether with two or more first additives selected from a first polarity polyolefin resin, a block copolymer impact modifier, and a multifunctional reactant, and three or more second additives selected from a second polarity polyolefin resin, a second polyester, carbon nanotubes having a specific BET, and plate-like carbon nanoplates in a predetermined composition ratio, a molded article including such a conductive resin composition has a sea-and-island structure that provides a continuous phase (sea), a dispersed phase (island), and additional dispersed phases (sub-islands) within the continuous phase, thereby exhibiting excellent appearance, rigidity, and conductivity, and at the same time being hardly affected by moisture and heat when exposed to the external environment. Based on this, the present inventors have conducted further research and have completed the present invention.

[0022] The conductive resin composition of the present invention is characterized by comprising (A) 100 parts by weight of a base resin including a first polyester and a polyarylene ether; (B) 8 to 20 parts by weight of two or more first additives selected from a first polar polyolefin resin, a block copolymer impact modifier, and a multifunctional reactant; and (C) 4 to 14 parts by weight of three or more second additives selected from a second polar polyolefin resin, a second polyester, carbon nanotubes, and carbon nanoplates. In this case, the conductive resin composition has excellent appearance, rigidity, and conductivity, as well as excellent moisture stability and heat resistance, thereby minimizing the effects of moisture and heat due to exposure to the external environment. As a result, it is particularly useful for use as a substitute for metal exterior parts in automobiles.

[0023] In another example, the present invention provides a coating composition comprising: (A) 100 parts by weight of a base resin including a first polyester and a polyarylene ether; (B) 8 to 20 parts by weight of two or more first additives selected from a first polar polyolefin resin, a block copolymer impact modifier, and a polyfunctional reactant; and (C) 4 to 14 parts by weight of three or more second additives selected from a second polar polyolefin resin, a second polyester, carbon nanotubes, and carbon nanoplates; A sea-and-island structure (Sea and Island) is provided, which provides a continuous phase (Sea), a dispersed phase (Island), and an additional dispersed phase (Sub Island), the continuous phase (Sea) is composed of the first polyester in the (A) base resin, the first polar polyolefin resin and the polyfunctional reactant in the (B) first additive, and the second polar polyolefin resin in the (C) second additive; the dispersed phase (islands) are constituted by the polyarylene ether in the (A) base resin, The additional dispersed phase (Sub Island) is characterized by being composed of the block copolymer impact modifier in the first additive (B) and the carbon nanotubes and carbon nanoplates in the second additive (C). In this case, the polymer has excellent moisture stability and heat resistance as well as excellent appearance, rigidity, and conductivity, minimizing the effects of moisture and heat due to exposure to the external environment. This makes the polymer particularly useful for applications as an alternative to metal exterior parts in automobiles.

[0024] In another example, the conductive resin composition of the present invention includes 100 parts by weight of a base resin including polyester and polyarylene ether, 1 to 20 parts by weight of a block copolymer impact modifier, 1 to 20 parts by weight of a polyfunctional reactant, and 0.1 to 10 parts by weight of one or more selected from carbon nanotubes and carbon nanoplates, and has a surface resistance of 10 8 It is characterized by its electrical resistance being ohm / sq or less, and in this case, it has the advantage of being excellent in balance of physical properties, heat resistance, conductivity, moisture stability and appearance quality.

[0025] In yet another example, the conductive resin composition of the present invention includes the steps of kneading and extruding (A) 100 parts by weight of a base resin including a first polyester and a polyarylene ether, (B) 8 to 20 parts by weight of two or more first additives selected from a first polar polyolefin resin, a block copolymer impact modifier, and a polyfunctional reactant, and (C) 4 to 14 parts by weight of three or more second additives selected from a second polar polyolefin resin, a second polyester, carbon nanotubes, and carbon nanoplates, using an extruder having nine or more kneading blocks, to provide a continuous phase (Sea), a dispersed phase (Island), and a sea-and-island structure providing additional dispersed phases (Sub Islands) within the continuous phase; The continuous phase (Sea) is composed of the first polyester in the (A) base resin, the first polar polyolefin resin and the multifunctional reactant in the (B) first additive, and the second polar polyolefin resin in the (C) second additive; the dispersed phase (Island) is composed of the polyarylene ether in the (A) base resin; and the additional dispersed phase (Sub-Island) is composed of the block copolymer impact modifier in the (B) first additive, and the carbon nanotubes and carbon nanoplates in the (C) second additive. In this case, the composition has excellent appearance, rigidity, and conductivity, as well as excellent moisture stability and heat resistance. This minimizes the effects of moisture and heat due to exposure to the external environment, making it particularly useful for applications as a metal replacement exterior part for automobiles.

[0026] Each component constituting the conductive resin composition of the present invention will be described in detail below.

[0027] (A) Base resin The base resin (A) of the present invention may be composed of a first polyester capable of providing the continuous phase (Sea) of the sea-and-island structure, and a polyarylene ether capable of providing the dispersed phase (Island).

[0028] 1st Polyester The first polyester described herein may preferably be one or more selected from polyalkylene terephthalate, poly(ester)urethane, and polyether ester, and more preferably is polyalkylene terephthalate, which has the effect of providing excellent appearance quality and electromagnetic wave shielding performance.

[0029] Specific examples of the polyalkylene terephthalate include one or more selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate, and polybutylene terephthalate is preferred. In this case, the polyalkylene terephthalate has the advantages of excellent appearance quality and electromagnetic wave shielding performance.

[0030] For example, the polybutylene terephthalate can be obtained through polymerization by esterification of butane-1,4-diol and terephthalic acid, or transesterification of butane-1,4-diol and dimethyl terephthalate.

[0031] The polyester resin may preferably be a copolymer or homopolymer containing 70 to 100% by weight of alkylene terephthalate as a repeating unit.

[0032] In this description, the weight ratio of the repeating units in a resin or copolymer may be a value calculated by converting the repeating units into monomers, or may be the weight ratio of the monomers added when the resin or copolymer is polymerized.

[0033] The alkylene terephthalate copolymer may be, for example, one formed by a transesterification reaction between 70 to 100% by weight, preferably 70 to 99% by weight, of butylene terephthalate and 0 to 30% by weight, preferably 1 to 30% by weight, of ethylene terephthalate or propylene terephthalate.

[0034] The first polyester may be contained in an amount of preferably 51 to 74% by weight, more preferably 55 to 72% by weight, and even more preferably 60 to 70% by weight of the base resin, and within this range, excellent conductivity, appearance quality, and moisture stability are all achieved.

[0035] The first polyester may have a melt index (250°C, 2.16 kg) expressed as MI of preferably 5 to 50 g / 10 min, more preferably 10 to 40 g / 10 min, even more preferably 15 to 35 g / 10 min, and even more preferably 20 to 30 g / 10 min. Within this range, the first polyester has the effect of exhibiting excellent conductivity, heat resistance, and electromagnetic wave shielding performance.

[0036] As an example, the first polyester may be a chemically modified polyester, preferably a modified polyalkylene terephthalate, and more preferably a modified polybutylene terephthalate, in which case impact strength and the like can be further improved.

[0037] For example, the chemical modification may be carried out by copolymerizing a main monomer such as alkylene terephthalate with at least one comonomer selected from the group consisting of polytetramethylene glycol (PTMG), polypropylene glycol (PPG), polyethylene glycol (PEG), low molecular weight aliphatic polyesters, and low molecular weight aliphatic polyamides.

[0038] Unless otherwise specified, the method for producing the first polyester is not particularly limited as long as it is a method commonly used in the technical field to which the present invention pertains, and examples thereof include interfacial polymerization, melt condensation polymerization, solution condensation polymerization, and transesterification.

[0039] Polyarylene Ether The polyarylene ether described herein is preferably polyphenylene ether (PPE), and specific examples thereof may be one or more selected from the group consisting of poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, poly(2-methyl-6-propyl-1,4-phenylene) ether, poly(2-ethyl-6-propyl-1,4-phenylene) ether, poly(2,6-diphenyl-1,4-phenylene) ether, poly(2,3,6-trimethyl-1,4-phenylene) ether, poly(2,3,6-triethyl-1,4-phenylene) ether, and copolymers thereof, and preferably poly(2,6-dimethyl-1,4-phenylene) or a copolymer thereof.

[0040] The polyarylene ether may be contained in an amount of preferably 26 to 49% by weight, more preferably 28 to 45% by weight, and even more preferably 30 to 40% by weight relative to the base resin, which has the effect of providing excellent heat resistance and mechanical strength.

[0041] The polyarylene ether copolymer refers to a polymer obtained by copolymerizing a main monomer and a comonomer introduced during polymerization. Specific examples thereof include a copolymer of poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,3,6-trimethyl-1,4-phenylene) ether; a copolymer of poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,3,6-triethyl-1,4-phenylene) ether; and combinations thereof. A preferred example is a copolymer of poly(2,6-dimethyl-1,4-phenylene) ether and poly(2,3,6-trimethyl-1,4-phenylene) ether.

[0042] The polyarylene ether may preferably have an intrinsic viscosity of 0.2 to 0.8 dL / g, more preferably 0.3 to 0.6 dL / g, and even more preferably 0.3 to 0.4 dL / g, as measured in chloroform at 25°C. Within this range, excellent mechanical properties are maintained, while excellent heat resistance, processability, and appearance quality are achieved.

[0043] The polyarylene ether may be in the form of a powder or Flake-shaped materials can be used, and particularly, flake-shaped materials have excellent mechanical properties such as impact strength and bending strength, as well as excellent processability and appearance quality.

[0044] In this description, the thickness and length of the flakes can be measured through microscopic analysis.

[0045] (B) First additive The first additive described herein may include a first polar polyolefin resin that can partially provide the continuous phase (Sea) of the sea-island structure together with the base resin, a multifunctional reactant, and a block copolymer impact modifier that can provide an additional dispersed phase (Sub Island) inside the dispersed phase (Island) of the sea-island structure.

[0046] The first additive may be included in an amount of, for example, 8 to 20 parts by weight, more preferably 8 to 18 parts by weight, even more preferably 9 to 18 parts by weight, and even more preferably 10 to 17.5 parts by weight, relative to 100 parts by weight of the base resin. Within this range, excellent mechanical properties, conductivity, etc., as well as excellent appearance quality and moisture stability can be achieved.

[0047] First polar polyolefin resin The first polar polyolefin resin described herein is preferably a copolymer in which a hydroxy group-containing ethylenically unsaturated compound, an amino group-containing ethylenically unsaturated compound, an epoxy group-containing ethylenically unsaturated compound, an aromatic vinyl compound, an unsaturated carboxylic acid and its derivatives, a vinyl ester compound, or vinyl chloride is grafted onto a polyolefin resin. In particular, the first polar polyolefin resin may be a copolymer in which an unsaturated carboxylic acid or its anhydride monomer or derivative is grafted onto the polyolefin resin. In this case, the first polar polyolefin resin has the effect of providing excellent electrical conductivity while also providing excellent mechanical properties such as impact strength.

[0048] Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornene dicarboxylic acid, and bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylic acid. Examples of these anhydride monomers or derivatives include malenyl chloride, malenylimide, maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylic anhydride, dimethyl maleate, monomethyl maleate, diethyl maleate, diethyl fumarate, dimethyl itaconate, diethyl citraconate, dimethyl tetrahydrophthalate, dimethyl bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, aminoethyl methacrylate, and aminopropyl methacrylate. Specifically, the modified polyolefin resin may be a copolymer in which acrylic acid or maleic anhydride is grafted onto a polyolefin resin.

[0049] The content of the unsaturated carboxylic acid may be, for example, 0.1 to 5 wt %, specifically 0.5 to 5 wt %, and preferably 0.8 to 3 wt %, based on 100 wt % of all components constituting the polar polyolefin resin, which has the effect of providing excellent conductivity while also providing excellent mechanical properties such as impact strength.

[0050] The first polar polyolefin resin may be contained in an amount of preferably 1 to 3 parts by weight, more preferably 1.2 to 2.8 parts by weight, and even more preferably 1.5 to 2.5 parts by weight, relative to 100 parts by weight of the base resin. Within this range, excellent mechanical properties, conductivity, etc., as well as excellent appearance quality and moisture stability can be achieved.

[0051] The method for producing the first polar polyolefin resin is not particularly limited as long as it is a method commonly used in the technical field to which the present invention pertains, and as a specific example, it can be obtained by heating a monomer such as the unsaturated carboxylic acid in the presence or absence of a radical initiator to cause a craft polymerization reaction. Graft polymerization is particularly preferably carried out in the presence of a radical initiator from the viewpoint of increasing the efficiency of the graft polymerization reaction.

[0052] Block Copolymer Impact Modifier The block copolymer impact modifier described herein may preferably be a styrene-based rubber, and specific examples thereof may be one or more selected from the group consisting of styrene-butadiene-styrene copolymer (SBS), styrene-ethylene-butylene-styrene copolymer (SEBS), styrene-butadiene copolymer (SB), styrene-isoprene copolymer (SI), styrene-isoprene-styrene copolymer (SIS), α-methylstyrene-butadiene copolymer, styrene-ethylene-propylene copolymer, styrene-ethylene-propylene-styrene copolymer, styrene-(ethylene-butylene / styrene copolymer)-styrene copolymer, and modified polymers thereof. Preferred examples thereof include one or more selected from the group consisting of styrene-butadiene-styrene copolymer (SBS), styrene-ethylene-butylene-styrene copolymer (SEBS), and maleic anhydride-modified styrene-ethylene-butylene-styrene copolymer, and more preferred examples thereof are styrene-butadiene-styrene copolymer (SBS). In this case, the effect of excellent conductivity is achieved while also exhibiting excellent mechanical properties such as impact strength.

[0053] The block copolymer impact modifier may be included in an amount of preferably 3 to 11 parts by weight, more preferably 4 to 10.5 parts by weight, and even more preferably 5 to 10 parts by weight, per 100 parts by weight of the base resin. Within this range, excellent mechanical properties, conductivity, etc., as well as excellent appearance quality and moisture stability can be achieved.

[0054] The block copolymer impact modifier may preferably have a content of structural units derived from aromatic vinyl compounds of 20 to 40% by weight, more preferably 20 to 30% by weight, and within this range, it has the effect of providing excellent mechanical properties.

[0055] The block copolymer impact modifier may preferably have a rubber component content of 60 to 80% by weight, more preferably 70 to 80% by weight, and within this range, it is effective in achieving excellent mechanical properties.

[0056] The block copolymer impact modifier is preferably dispersed in a sea-and-island structure with an average particle size of 0.5 μm or less, more preferably 0.3 μm or less, to form an additional dispersed phase (sub-island) within the dispersed phase (island). Within this range, excellent heat resistance and impact strength can be obtained.

[0057] Here, unless otherwise specified, the additional dispersed phase may refer to an additional dispersed phase provided inside a dispersed phase (Sub Island in Island, corresponding to the part marked "Sub Island" in Figure 2).

[0058] In this description, the average particle size can be measured using dynamic light scattering. Specifically, it is measured as an intensity value in Gaussian mode using a particle size analyzer (product name: Nicomp380, manufacturer: PSS). As a specific measurement example, 0.1 g of latex with a total solids content of 35-50 wt% is prepared as a sample by diluting it 1,000-5,000 times with distilled water. The measurement method is auto-dilution followed by measurement using a flow cell. The measurement mode is dynamic light scattering / intensity 300 kHz / intensity-weighted Gaussian analysis, with the following settings: temperature 23°C, measurement wavelength 632.8 nm, and channel width 10 μsec.

[0059] The method for producing the block copolymer impact modifier is not particularly limited as long as it is a method commonly used in the technical field to which the present invention pertains. Specific examples include emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization, and preferred examples include emulsion polymerization and bulk polymerization.

[0060] Multifunctional Reactants The polyfunctional reacting agent described herein preferably contains two or more, specifically 2 to 5, functional groups selected from the group consisting of a carboxy group, an amine group, a hydroxy group, a maleic acid group, and an epoxy group, and in this case, has the effect of providing excellent conductivity and moisture stability.

[0061] In this description, the maleic acid group is not particularly limited as long as it is a substituent recognized as a maleic acid group in the technical field to which the present invention pertains, and specifically refers to a functional group derived from maleic acid or maleic anhydride.

[0062] A specific example of the polyfunctional reactant may be a polymer functionalized by reacting polyphenylene ether with a reactive monomer such as an unsaturated carboxylic acid or anhydride thereof.

[0063] The reactive monomer may be, for example, one or more selected from the group consisting of citric acid, maleic acid, itaconic acid, fumaric acid, acrylic acid, and anhydrides thereof.

[0064] Two or more types of the polyfunctional reacting agent can be used, and the term "two or more types" means that there are two or more polyfunctional reacting agents different in type or structure.

[0065] As a specific example, the polyfunctional reactant is preferably a combination of one polymeric polyfunctional reactant having a number average molecular weight of 150,000 g / mol or more and one low molecular weight polyfunctional reactant having a number average molecular weight of 10,000 g / mol or less.

[0066] The polyfunctional reactant may be preferably contained in an amount of 2 to 12 parts by weight, more preferably 2.5 to 12 parts by weight, and even more preferably 3 to 12 parts by weight, based on 100 parts by weight of the base resin. Within this range, there are advantages in that the inherent mechanical properties of the resin are not deteriorated, and the appearance quality, conductivity, and moisture stability are significantly improved.

[0067] The polyfunctional reactant used in the present description may preferably include one or more selected from polyphenylene oxide resins functionalized with carboxylic acid, maleic acid, or maleic anhydride, and bisphenol A-type epoxy resins having terminal epoxy functional groups. In this case, excellent conductivity and moisture stability can be obtained.

[0068] The polyphenylene oxide resin functionalized with the carboxylic acid, maleic acid, or maleic anhydride may be contained in an amount of preferably 1 to 10 parts by weight, more preferably 2 to 8 parts by weight, and even more preferably 3 to 7 parts by weight, based on 100 parts by weight of the total base resin. Within this range, the inherent mechanical properties of the resin are not deteriorated, and there are advantages in that the appearance quality and moisture stability are significantly improved.

[0069] The bisphenol A type epoxy resin may be preferably contained in an amount of 0.5 to 8 parts by weight, more preferably 1 to 7 parts by weight, and even more preferably 1 to 5 parts by weight, based on 100 parts by weight of the total base resin. Within this range, the inherent mechanical properties of the resin are not deteriorated, and the appearance quality, conductivity, and moisture stability are significantly improved.

[0070] The bisphenol A epoxy resin preferably has an average epoxy equivalent of 2,000 to 6,000, and / or a number average molecular weight of 3,000 to 10,000 g / mol, and / or a glass transition temperature of 50 to 120°C, and / or may be solid at room temperature (22 to 25°C). Within these ranges, the inherent mechanical properties of the resin are not impaired, and there are advantages in that the appearance quality and moisture stability are greatly improved.

[0071] In this description, the number average molecular weight (Mn) can be measured using GPC (Gel Permeation Chromatography, water breeze).

[0072] In this description, the glass transition temperature (Tg) can be measured using a Perkin Elmer Pyris 6 DSC.

[0073] In this description, the average epoxy equivalent weight is the average molecular weight per epoxy group.

[0074] The polyphenylene oxide resin functionalized with a carboxylic acid, maleic acid, or maleic anhydride may be contained in an amount of preferably 0.5 to 8 parts by weight, more preferably 1 to 7 parts by weight, and even more preferably 2 to 7 parts by weight, based on 100 parts by weight of the total base resin. Within this range, the continuous phase (Sea) is reinforced in the sea-island structure, thereby providing the advantage of significantly improving heat resistance and moisture stability.

[0075] In the present description, the polyfunctional reacting agent is not particularly limited, and may be one prepared by a method commonly used in the technical field to which the present invention pertains, or may be a commercially available product, as long as it meets the definition of the present invention.

[0076] (C) Second additive The second additive described herein can include a second polar polyolefin resin and a second polyester that can reinforce the continuous phase (Sea) of the aforementioned sea-island structure, and carbon nanotubes and carbon nanoplates that can provide an additional dispersed phase (Sub Island).

[0077] The second additive may be included in an amount of, for example, 4 to 14 parts by weight, more preferably 4 to 12 parts by weight, even more preferably 4 to 10 parts by weight, and even more preferably 5 to 9 parts by weight, relative to 100 parts by weight of the base resin. Within this range, excellent mechanical properties, conductivity, etc., as well as excellent appearance quality and moisture stability can be achieved.

[0078] The second additive may be prepared and introduced as a masterbatch, where it may provide an additional dispersed phase within the continuous phase while reinforcing the continuous phase.

[0079] The second additive may be produced by kneading and extruding the second additive using an extruder having, for example, 9 or more, preferably 10 or more, more preferably 12 or more, preferably 9 to 18, more preferably 10 to 18, and even more preferably 12 to 16 kneading blocks. It is effective to use kneading blocks in a combination of forward, perpendicular, and reverse directions relative to the resin flow direction. Depending on the mixing method, a combination of continuous or separated blocks may be used. This further improves the dispersibility of the components and the compatibility of the composition, thereby providing a masterbatch of higher quality.

[0080] Secondary polarity polyolefin resin The second polar polyolefin resin of the present invention can be selected from the types of the first polar polyolefin resin described above in section (B).

[0081] The second polarity polyolefin resin may be contained in an amount of preferably 70 to 100% by weight, more preferably 75 to 100% by weight, and even more preferably 80 to 100% by weight, based on 100% by weight of the base resin composed of the second polarity polyolefin resin and the second polyester described below. Within this range, the continuous phase (Sea) of the sea-island structure is reinforced, thereby having the advantage of significantly improving the conductivity, mechanical properties, and moisture stability of the base resin.

[0082] Second Polyester The second polyester described herein can be selected from the types described above for the first polyester in item (A).

[0083] The second polyester may be contained in an amount of 0 to 30% by weight, more preferably 0 to 25% by weight, and even more preferably 1 to 20% by weight, based on 100% by weight of the base resin composed of the second polar polyolefin resin and the second polyester. Within this range, the second polyester helps reinforce the continuous phase (Sea) of the sea-island structure, thereby improving the conductivity, mechanical properties, and moisture stability of the base resin.

[0084] carbon nanotubes The carbon nanotubes described herein preferably have a BET surface area of ​​180 to 600 m 2 / g, more preferably 180 to 400m 2 / g, more preferably 180 to 300m 2 / g, more preferably 200 to 300m 2 / g, and within this range, the effects of improving processability and conductivity are significant.

[0085] In this description, the BET surface area can be measured by a nitrogen adsorption method. Specifically, the BET surface area can be measured by a BET 6-point method using a nitrogen gas adsorption flow method using a porosimetry analyzer (Belsorp-II mini, Bell Japan Inc.). Another example is the Brunauer, Emmett, and Teller method (a method in accordance with ASTM 6556).

[0086] The carbon nanotubes may be included in an amount of, for example, 10 to 40 parts by weight, preferably 10 to 30 parts by weight, more preferably 20 to 30 parts by weight, and even more preferably 20 to 25 parts by weight, based on 100 parts by weight of the base resin composed of the second polarity polyolefin resin and the second polyester. Within this range, excellent mechanical properties, processability, and conductivity can be achieved, while also achieving excellent appearance quality and heat resistance.

[0087] For example, the carbon nanotube may be at least one selected from the group consisting of a single-walled carbon nanotube (SWCNT), a double-walled carbon nanotube (DWCNT), and a multi-walled carbon nanotube (MWCNT).

[0088] For example, the carbon nanotubes may be of a bundle (rope) type or a non-bundle (entangle) type.

[0089] In this description, the terms "bundled type" and "non-bundled type" are not particularly limited as long as they are "bundled type" and "non-bundled type" that are generally recognized or defined in the technical field to which the present invention pertains.

[0090] The carbon nanotubes may preferably have an average diameter of 5 to 30 nm, more preferably 7 to 20 nm, and even more preferably 10 to 15 nm. Within this range, conductivity, appearance quality, and the like are significantly improved.

[0091] In this description, the average diameter of carbon nanotubes is not particularly limited as long as it is measured by a measurement method commonly used in the technical field to which the present invention pertains, and as a specific example, it can be measured by electron microscopy analysis.

[0092] The carbon nanotubes may be preferably provided in a fibrous form, and in this case, they may be dispersed in a sea-and-island structure with a size of 1.0 μm or less, forming an additional dispersed phase within the continuous phase, as shown in Figure 2. Here, the additional dispersed phase refers to an additional dispersed phase (sub-island in sea, not shown in Figure 2) dispersed within the continuous phase, and is defined as being different from the additional dispersed phase (sub-island in island, indicated as "sub-island" in Figure 2) provided by the block copolymer impact modifier described above.

[0093] carbon nanoplates The carbon nanoplates described herein are preferably plate-shaped carbon nanoplates, more preferably plate-shaped carbon nanoplates having an average thickness of 5 to 50 nm. Within this range, the mutual dispersion effect with the carbon nanotubes described above has the advantage of significantly improving the conductivity, mechanical properties, heat resistance, and moisture stability of the base resin.

[0094] The carbon nanoplates may preferably include at least one selected from exfoliated graphite, graphene nanoplates, and exfoliated expandable graphite, and more preferably exfoliated graphite. Within this range, the conductivity, mechanical properties, heat resistance, and moisture stability of the base resin can be significantly improved due to the mutual dispersion effect with the carbon nanotubes.

[0095] The exfoliated graphite may be, for example, graphite obtained by processing layered graphite to a thickness of 5 to 50 nm through a chemical and / or physical exfoliation method.

[0096] The chemical and / or physical exfoliation method of the layered graphite is not particularly limited as long as it is an exfoliation method commonly used in the technical field to which the present invention pertains. For example, the method may involve modifying and expanding graphite using the Brodie method, Hummers method, etc., and then exfoliating the graphite through ultrasonic pulverization, rapid heating, etc.

[0097] The carbon nanoplates may be included in an amount of, for example, 1 to 10 parts by weight, more preferably 2 to 8 parts by weight, even more preferably 3 to 8 parts by weight, and even more preferably 3 to 7 parts by weight, based on 100 parts by weight of the base resin composed of the second polar polyolefin resin and the second polyester. Within this range, the conductivity, mechanical properties, and moisture stability of the base resin are significantly improved due to the mutual dispersion effect with the carbon nanotubes.

[0098] In addition, the carbon nanoplates may be preferably contained in an amount of 0.4 to 1.4 parts by weight, more preferably 0.4 to 1.2 parts by weight, and even more preferably 0.5 to 1 part by weight, based on 100 parts by weight of the base resin composed of the second polar polyolefin resin and the second polyester. Within this range, the conductivity, mechanical properties, and moisture stability of the base resin can be further improved due to the mutual dispersion effect with the carbon nanotubes.

[0099] The carbon nanoplates may have an average thickness of more preferably 5 to 40 nm, and even more preferably 10 to 40 nm. Within this range, the mutual dispersion effect with the carbon nanotubes described above has the effect of simultaneously improving conductivity and appearance properties.

[0100] In this description, the average thickness of the carbon nanoplates is not particularly limited as long as it is measured by a measurement method commonly used in the technical field to which the present invention belongs, and as a specific example, it can be measured using an electron microscope analysis method.

[0101] The carbon nanoplates may be preferably provided in a plate-like form, and in this case, they may be dispersed in a sea-island structure with a size of 1.0 μm or less, as shown in Figure 2, and may constitute an additional dispersed phase in the continuous phase together with the carbon nanotubes. Here, the additional dispersed phase is an additional dispersed phase (Sub Island in Sea) dispersed in the continuous phase, and is defined differently from the additional dispersed phase (Sub Island in Island) provided by the block copolymer impact modifier.

[0102] Conductive resin composition For example, the conductive resin composition described herein may be prepared as a masterbatch with the second additive to provide a sea-and-island structure that provides a continuous phase (sea), a dispersed phase (island), and an additional dispersed phase (sub-island) within the continuous phase.

[0103] The continuous phase may be composed of a first polyester in the (A) base resin, a first polar polyolefin resin and a multifunctional reactant in the (B) first additive, and a second polar polyolefin resin in the (C) second additive. The dispersed phase may be composed of a polyarylene ether in the (A) base resin. The additional dispersed phase may be composed of a block copolymer impact modifier in the (B) first additive, and carbon nanotubes and carbon nanoplates in the (C) second additive. In this case, the composition exhibits excellent moisture stability and heat resistance in addition to excellent appearance, rigidity, and conductivity, minimizing the effects of moisture and heat due to exposure to the external environment. This makes the composition particularly useful for automotive exterior parts as a replacement for metal.

[0104] The conductive resin composition of the present invention preferably has a heat distortion temperature of 170°C or higher, more preferably 170 to 200°C, preferably 170 to 195°C, and even more preferably 180 to 190°C. Within this range, the conductive resin composition has the advantages of an excellent balance of physical properties, moisture stability, conductivity, and appearance quality.

[0105] The conductive resin composition preferably has a moisture absorption rate of 0.1% or less, 0.094% or less, 0.93% or less, or 0.092% or less, specifically 0.05 to 0.094%, preferably 0.06 to 0.092%, and more preferably 0.06 to 0.09%. Within this range, the conductive resin composition has the advantages of an excellent balance of physical properties, and excellent heat resistance, conductivity, and appearance quality.

[0106] The water absorption rate was measured by the method used in the examples described later, and can be calculated using the following equation 1, for example.

[0107] [Formula 1] Water absorption rate (%) = (weight increase after immersion / weight before immersion) x 100

[0108] The conductive resin composition preferably has a surface resistance of 10 7 ohm / sq or less, for example, 10 7 ~10 8 Within this range, the material has an excellent balance of physical properties, and is advantageous in terms of heat resistance, moisture stability, and appearance quality.

[0109] The conductive resin composition preferably has a tensile strength of 55 MPa or more, specifically 55 to 70 MPa, and preferably 55 to 65 MPa, when measured in accordance with the ASTM D638 method using a test piece of 3.2 mm thickness and at a measurement speed of 5 mm / min. Within this range, the conductive resin composition has advantages such as an excellent balance of physical properties, heat resistance, conductivity, moisture stability, and appearance quality.

[0110] The conductive resin composition preferably has a notched Izod impact strength of 100 J / m or more, more preferably 110 J / m or more, specifically 110 to 180 J / m, and preferably 110 to 175 J / m, when measured in accordance with the ISO 180A method using a test piece with a thickness of 4 mm at a measurement temperature of 25°C. Within this range, the conductive resin composition has the advantages of an excellent balance of physical properties, and excellent heat resistance, conductivity, moisture stability, and appearance quality.

[0111] As an example, the conductive resin composition of the present invention, as confirmed in the following examples and comparative examples, comprises 100 parts by weight of a base resin including polyester and polyarylene ether; 1 to 20 parts by weight of a block copolymer impact modifier; 1 to 20 parts by weight of a multifunctional reactant; and 0.1 to 10 parts by weight of one or more selected from carbon nanotubes and carbon nanoplates, and has a surface resistance of 10 8 It is characterized by its electrical resistance being ohm / sq or less, and in this case, it has the advantage of being excellent in balance of physical properties, heat resistance, conductivity, moisture stability and appearance quality.

[0112] The term "polyester" used here includes the first polyester and the second polyester described above.

[0113] When polyamides such as nylon 6 and nylon 66 were included, the effect of providing an alloy with stabilized moisture properties was not observed or was reduced (see Comparative Example 5 below).

[0114] Method for producing conductive resin composition The method for producing the conductive resin composition of the present invention preferably includes the steps of kneading and extruding (A) 100 parts by weight of a base resin including a first polyester and a polyarylene ether; (B) 8 to 20 parts by weight of two or more first additives selected from a first polar polyolefin resin, a block copolymer impact modifier, and a polyfunctional reactant; and (C) 4 to 14 parts by weight of three or more second additives selected from a second polar polyolefin resin, a second polyester, carbon nanotubes, and carbon nanoplates, using an extruder having nine or more kneading blocks to form a continuous phase, a dispersed phase, and a sea-and-island structure that provides an additional dispersed phase within the continuous phase, The continuous phase (Sea) is composed of the first polyester in the (A) base resin, the first polar polyolefin resin and the multifunctional reactant in the (B) first additive, and the second polar polyolefin resin in the (C) second additive; the dispersed phase (Island) is composed of the polyarylene ether in the (A) base resin; and the additional dispersed phase (Sub-Island) is composed of the block copolymer impact modifier in the (B) first additive, and the carbon nanotubes and carbon nanoplates in the (C) second additive. In this case, the conductive resin composition has excellent appearance, rigidity, and conductivity, as well as excellent moisture stability and heat resistance, minimizing the effects of moisture and heat due to exposure to the external environment. This provides an advantageous conductive resin composition that is particularly useful for applications in automotive exterior parts that replace metal.

[0115] The kneading and extrusion can be carried out within a barrel temperature range of, for example, 230 to 310°C, preferably 240 to 300°C, more preferably 250 to 290°C, and even more preferably 250 to 280°C. In this case, there are advantages that sufficient melt-kneading is possible while the throughput per unit time is high, and problems such as thermal decomposition of the resin component do not occur.

[0116] The kneading and extrusion may be carried out under conditions where the screw rotation speed is, for example, 100 to 500 rpm, preferably 150 to 400 rpm, more preferably 100 to 350 rpm, even more preferably 150 to 320 rpm, and even more preferably 200 to 310 rpm. Within this range, the throughput per unit time is high and the process efficiency is excellent, while excessive scission of the carbon nanotubes and carbon nanoplates is suppressed, resulting in superior conductivity of the final product.

[0117] The conductive resin composition obtained through the kneading and extrusion may be provided preferably in the form of pellets.

[0118] The method for producing a molded article described herein preferably includes the steps of: kneading and extruding (A) 100 parts by weight of a base resin including a first polyester and a polyarylene ether; (B) 8 to 20 parts by weight of two or more first additives selected from a first polar polyolefin resin, a block copolymer impact modifier, and a polyfunctional reactant; and (C) 4 to 14 parts by weight of three or more second additives selected from a second polar polyolefin resin, a second polyester, carbon nanotubes, and carbon nanoplates to produce conductive resin composition pellets; and injecting the produced pellets to produce a molded article. The second additives are prepared and added as a masterbatch, and the kneading and extrusion are carried out using an extruder having nine or more kneading blocks. In this case, the molded article has excellent appearance, rigidity, and conductivity, as well as excellent moisture stability and heat resistance, and is therefore effective in minimizing the effects of moisture and heat due to exposure to the external environment.

[0119] The injection may be carried out by any method and under any conditions commonly used in the technical field to which the present invention pertains, and is not particularly limited, and may be appropriately selected and applied as needed.

[0120] In the description of the conductive resin composition, molded article and manufacturing method thereof, other conditions not specifically specified (for example, the configuration and specifications of the extruder and injector, extrusion and injection conditions, additives, etc.) are not particularly limited as long as they are within the range commonly used in the art, and can be appropriately selected as needed.

[0121] The present invention will now be described with reference to the drawings.

[0122] FIG. 1 below is a schematic diagram of an extruder equipped with nine or more kneading blocks for producing the conductive resin composition of the present invention.

[0123] The type of extruder is not particularly limited, and any extruder commonly used in the industry may be appropriately selected. For example, a single-screw extruder having one screw or a multi-screw extruder having multiple screws may be used. In consideration of uniform mixing of materials, ease of processing, and economy, it is preferable to use a twin-screw extruder having two screws.

[0124] The extruder is composed of a feeder for supplying materials into a barrel, a screw for transporting and kneading the materials supplied into the barrel, and a die for extruding the kneaded materials, and the screw is composed of multiple screw elements to provide various functions.

[0125] The number of the raw material supplier may be one or more, and two or more may be provided selectively as needed. For example, a main inlet and a selective auxiliary inlet may be provided, and two or more auxiliary inlets may be provided as needed.

[0126] In one specific example, all components may be simultaneously added to the main inlet, or in another example, the base resin and the first additive may be added to the main inlet, and the second additive may be added to the auxiliary inlet.

[0127] The kneading block of the present invention is an example of the screw element, and specifically, is composed of a plurality of disks, preferably 3 to 7, 5 to 7, 3 to 5, or 4 to 5 disks, usually with a polygonal or elliptical cross section, and arranged continuously in the material transport direction. Furthermore, the phase angle of the disks in the kneading block (meaning the movement angle between the disks) is preferably 45 to 90°.

[0128] In addition, kneading blocks include forward kneading blocks that have the ability to transport, distribute, and mix materials, neutral kneading blocks that have only the ability to distribute and mix materials without the ability to transport materials, and backward kneading blocks that transport materials in the opposite direction to the transport direction.

[0129] The conductive resin composition according to the present invention may be produced by kneading and extruding using an extruder having, for example, 9 or more, preferably 10 or more, more preferably 12 or more, preferably 9 to 18, more preferably 10 to 18, and even more preferably 12 to 16 kneading blocks. It is effective to use kneading blocks in combination in the order of forward, perpendicular, and reverse directions relative to the resin flow direction, and a combination of continuous or separated blocks may be used depending on the mixing method. In this case, the dispersibility of the conductive filler component and the compatibility of the composition may be further improved, thereby providing a conductive resin composition of higher quality.

[0130] For example, nine or more kneading blocks may be arranged continuously, or, for another example, they may be arranged discontinuously between the screws. Specifically, three to six kneading blocks may be arranged continuously between the main inlet and auxiliary inlet 1, three to eight kneading blocks may be arranged continuously between auxiliary inlet 1 and auxiliary inlet 2, and two to five kneading blocks may be arranged between auxiliary inlet 2 and the discharge port (not shown). This arrangement offers the advantages of controlling localized heat generation during melt-kneading, preventing thermal deformation of the raw materials, and preventing excessive scission of nanocomponents, thereby preventing degradation of electrical conductivity and mechanical properties.

[0131] FIG. 2 below shows the sea-island structure provided by the conductive resin composition of the present invention.

[0132] According to Figure 2 below, the first polyester in the (A) base resin, the first polar polyolefin resin and the polyfunctional reactant in the (B) first additive, and the second polar polyolefin resin in the (C) second additive constitute the continuous phase (Sea) of the sea-island structure, the polyarylene ether in the (A) base resin constitutes the dispersed phase (Island) of the sea-island structure, and the block copolymer impact modifier in the (B) first additive and the carbon nanotubes and carbon nanoplates in the (C) second additive constitute additional dispersed phases (Sub-Islands) of the sea-island structure.

[0133] Specifically, the block copolymer impact modifier may constitute a finer internal dispersed phase (Sub-Island in Island) within the dispersed phase of the sea-island structure.

[0134] In addition, the carbon nanotubes and carbon nanoplates can selectively form a fine internal dispersed phase (Sub Island in Sea) in the continuous phase of the sea-island structure.

[0135] When the carbon nanotubes are fibrous and the carbon nanoplates are plate-shaped, the dispersion effect can be further enhanced.

[0136] The term "sea and island structure" used in this description means a dispersed structure consisting of a continuous phase (sea) and a dispersed phase (islands), as is well known in the art.

[0137] The sea-island structure can be verified by, for example, observing the state of formation of the sea-island structure, the uniformity of its shape, the state of division, etc., using an optical microscope at a magnification of 200 times.

[0138] The sea-island structure provided by the conductive resin composition of the present invention is characterized by having a structure in which, in addition to the basic structure of the continuous phase (Sea) and dispersed phase (Island) described above, an additional dispersed phase (Sub-Island in Sea) is selectively dispersed in the continuous phase (Sea), and an additional dispersed phase (Sub-Island in Island) is dispersed within the dispersed phase (Island).

[0139] molded product Automotive molded products manufactured from the conductive resin composition have excellent dimensional stability even when exposed to moisture, and therefore have the effect of minimizing dimensional changes due to exposure to the external environment.

[0140] The molded article may be an electrostatically painted exterior part of an automobile.

[0141] The electrostatically painted exterior parts of the automobile may be, for example, exterior panels, doors, fuel filler ports, charging ports, etc.

[0142] Preferred examples are presented below to aid in understanding the present invention. However, the following examples are merely illustrative of the present invention, and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope of the scope and technical idea of ​​the present invention. Naturally, such changes and modifications also fall within the scope of the appended claims.

[0143] [Example] The components used in the following examples and comparative examples are as follows. *First polyester: Polybutylene terephthalate resin, LG Chemical's GP2000 (MI (250°C, 2.16 kg): 30 g / 10 min) product was used. * Second polyester: Polybutylene terephthalate resin, LG Chemical's GP2000 (MI (250°C, 2.16 kg): 30 g / 10 min) product was used. *Polyarylene ether: Bluestar's 040 product was used as polyphenylene oxide resin (PPO). *Polyamide: Invista's 3602 PA66 product was used. *First polar polyolefin resin: ethylene-octene copolymer (density: 0.87 g / cm 3 LC170 product from LG Chemicals, which is a terpolymer of PEG-14, was used after modification with 1.2 wt% maleic acid. * Second polar polyolefin resin: ethylene-octene copolymer (density: 0.87 g / cm 3 LC170 product from LG Chemicals, which is a terpolymer of PEG-14, was used after modification with 1.2 wt% maleic acid. *Block copolymer impact modifier: Kraton SEBS 1651 product (styrene content 32% by weight, butadiene rubber content 68% by weight) was used as the styrene-based rubber. * Multifunctional reactant 1: Kukdo Chemical's reactive epoxy YD019 product (epoxy equivalent weight 2,000-3,000) was used. *Multifunctional reactant 2: G Farm's ZA product with a maleic anhydride-modified polyphenylene oxide (mah-PPO) structure was used. *Carbon nanotubes: BET surface area is 200-300m 2 LG Chemical's carbon nanotube CP1002M fiber product with a capacity of 1 / g was used. *Carbon nanoplate: A layered exfoliated product with an average thickness of 5 to 50 nm was used.

[0144] Production Examples 1 to 3: Production of second additive <Production Example 1> 100 parts by weight of a second polarity polyolefin resin, 25 parts by weight of carbon nanotubes, and 5 parts by weight of plate-shaped carbon nanoplates were melt-kneaded using a twin-screw extruder (SM T40) with 10 kneading blocks, and then extruded to produce second additive pellets.

[0145] The cylinder temperature of the twin-screw extruder was set to 250° C., and the screw rotation speed was set to 300 rpm.

[0146] The pellets produced are listed as 'PMB1-25' in Table 1 below.

[0147] <Production Example 2> 100 parts by weight of a base resin composed of 80% by weight of a second polar polyolefin resin and 20% by weight of a second polyester, 25 parts by weight of carbon nanotubes, and 5 parts by weight of plate-shaped carbon nanoplates were melt-kneaded using a twin-screw extruder (SM T40) with 10 kneading blocks, and then extruded to produce second additive pellets.

[0148] The cylinder temperature of the twin-screw extruder was set to 250° C., and the screw rotation speed was set to 300 rpm.

[0149] The pellets produced are listed as 'PMB2-25' in Table 1 below.

[0150] <Production Example 3> 100 parts by weight of a second polarity polyolefin resin, 20 parts by weight of carbon nanotubes, and 5 parts by weight of plate-shaped carbon nanoplates were melt-kneaded using a twin-screw extruder (SM T40) with 10 kneading blocks, and then extruded to produce second additive pellets.

[0151] The cylinder temperature of the twin-screw extruder was set to 250° C., and the screw rotation speed was set to 300 rpm.

[0152] The pellets produced are listed as 'PMB3-20' in Table 1 below.

[0153] Examples 1 to 5 and Comparative Examples 1 to 5 The components and amounts shown in Tables 1 and 2 below were melt-mixed and extruded into pellets using a twin-screw extruder (SM T40) with 10 mixing blocks at a temperature of 250-310°C and a rotation speed (rpm) of 300 rpm. Test specimens for evaluation were then prepared from the pellets using an injector (Engel, 80 ton).

[0154] The components except for the first polyester were fed into the main inlet of the twin-screw extruder, the first polyester was fed into auxiliary inlet 1, and the pellets produced in the Production Example were fed into auxiliary inlet 2.

[0155] [Test example] The properties of the test pieces produced in Examples 1 to 5 and Comparative Examples 1 to 5 were measured by the following methods, and the results are shown in Tables 1 and 2 below. *Tensile strength (MPa): Measured using a 3.2 mm thick test piece at a measurement speed of 5 mm / min in accordance with ASTM D638 method. *Impact strength (J / m): Notched Izod impact strength was measured using a 4mm thick test piece in accordance with the ISO 180A method. After notching the test piece, it was measured at room temperature (23°C). *Heat distortion temperature (°C): Measured using a 4 mm thick test piece under a stress of 0.45 MPa in accordance with the ISO 75-2 method. *Surface resistance (Ohm / sq): The surface resistance of the injection test piece was measured using Prostat's PRS-801 equipment. *Surface quality (appearance): The appearance of the injection test piece was visually evaluated, with the following criteria: ◎: excellent moldability and appearance, ○: good moldability and appearance, △: good appearance (pinholes observed intermittently), ×: poor appearance (pinholes observed), XX: poor appearance (pinholes and flow marks observed). *Water absorption rate (%): Using an injection machine (80 ton, Engel), a flat plate test piece with dimensions of 100 mm x 100 mm x 3 mm was injected, and after immersing it in distilled water at 23°C for 48 hours, the weight increase was measured and calculated using the following formula 1.

[0156] [Formula 1] Water absorption rate (%) = (weight increase after immersion / weight before immersion) x 100

[0157] [Table 1]

[0158] [Table 2]

[0159] As shown in Tables 1 and 2, the conductive resin compositions according to the present invention (Examples 1 to 5) are significantly improved in mechanical properties such as tensile strength and impact strength, heat distortion temperature and surface resistance, and the surface quality and moisture absorption rate are far superior in all examples, compared to the conductive resin compositions outside the scope of the present invention (Comparative Examples 1 to 5).

[0160] On the other hand, in the case of Comparative Example 5 containing a polyamide such as nylon 66, the moisture absorption rate was significantly reduced compared to Examples 1 to 5, and it was confirmed that it was difficult to provide an alloy with stabilized moisture properties required for electrostatically painted exterior parts of automobiles.

[0161] That is, the conductive resin composition according to one embodiment of the present invention includes specific weight percents of (A) a base resin including a first polyester and a polyarylene ether; (B) two or more first additives selected from a first polar polyolefin resin, a block copolymer impact modifier, and a multifunctional reactant; and (C) three or more second additives selected from a second polar polyolefin resin, a second polyester, carbon nanotubes, and carbon nanoplates. The conductive resin composition reinforces the continuous phase in a sea-and-island continuous phase and disperse phase structure while providing additional disperse phase structures to the continuous phase and disperse phase, respectively. Electrostatically painted automotive exterior parts manufactured from the composition advantageously have improved heat resistance, conductive dispersion, and surface properties.

Claims

1. 100 parts by weight of a base resin (A) containing 51 to 74% by weight of polybutylene terephthalate and 26 to 49% by weight of polyarylene ether; 8 to 20 parts by weight of a first additive (B) containing 1 to 3 parts by weight of a copolymer obtained by grafting an unsaturated carboxylic acid or its anhydride or a derivative thereof onto a polyolefin resin, 3 to 11 parts by weight of a block copolymer impact modifier, and 2 to 12 parts by weight of a polyfunctional reactant; The composition comprises 100 parts by weight of a base resin containing 70 to 100% by weight of a copolymer obtained by grafting an unsaturated carboxylic acid or its anhydride or a derivative thereof onto a polyolefin resin and 0 to 30% by weight of polybutylene terephthalate, 10 to 40 parts by weight of carbon nanotubes, and 4 to 14 parts by weight of a pellet-type second additive (C) obtained by kneading and extruding 1 to 10 parts by weight of carbon nanoplates; providing a sea-island structure providing a continuous phase (sea), a dispersed phase (islands), additional dispersed phases in the continuous phase (sub-islands in the sea) and individual additional dispersed phases in the dispersed phase (sub-islands in the islands); the continuous phase (sea) comprises polybutylene terephthalate, a copolymer obtained by grafting an unsaturated carboxylic acid or its anhydride or a derivative thereof onto a polyolefin resin, and the polyfunctional reactant; the dispersed phase (islands) are made of the polyarylene ether, the additional dispersed phase (sub-islands in the sea) in the continuous phase consists of the carbon nanotubes and the carbon nanoplates; Each additional dispersed phase (sub-island within the island) in the dispersed phase consists of the block copolymer impact modifier. Conductive resin composition.

2. The conductive resin composition according to claim 1, wherein the polybutylene terephthalate has a melt index (250° C., 2.16 kg) of 5 to 50 g / 10 min.

3. The conductive resin composition according to claim 1, wherein the polyfunctional reactant comprises two or more functional groups selected from the group consisting of a carboxy group, an amine group, a hydroxy group, a maleic acid group, and an epoxy group.

4. 2. The conductive resin composition according to claim 1, wherein the polyfunctional reactant comprises at least one selected from the group consisting of polyphenylene oxide resins functionalized with carboxylic acid, maleic acid, or maleic anhydride, and bisphenol A-type epoxy resins.

5. The carbon nanotubes have a BET surface area of ​​180 to 600 m 2 The conductive resin composition according to claim 1, wherein the conductive resin composition has a molecular weight of 1000 or more and is fibrous.

6. The conductive resin composition according to claim 1, wherein the carbon nanoplates are plate-shaped with an average thickness of 5 to 50 nm.

7. The conductive resin composition according to claim 1 , wherein the conductive resin composition has a moisture absorption rate of 0.094% or less.

8. The conductive resin composition has a heat distortion temperature of 170° C. or more and a surface resistance of 10 7 The conductive resin composition according to claim 1, having a resistivity of ohm / sq or less.

9. a step of producing a pellet-type second additive (C) by kneading and extruding 100 parts by weight of a base resin containing 70 to 100% by weight of a copolymer obtained by grafting an unsaturated carboxylic acid or its anhydride or a derivative thereof onto a polyolefin resin and 0 to 30% by weight of polybutylene terephthalate, 10 to 40 parts by weight of carbon nanotubes, and 1 to 10 parts by weight of carbon nanoplates; The method comprises the steps of: kneading and extruding 100 parts by weight of a base resin (A) containing 51 to 74% by weight of polybutylene terephthalate and 26 to 49% by weight of polyarylene ether; 8 to 20 parts by weight of a first additive (B) containing 1 to 3 parts by weight of a copolymer obtained by grafting an unsaturated carboxylic acid or its anhydride or a derivative thereof onto a polyolefin resin, 3 to 11 parts by weight of a block copolymer impact modifier, and 2 to 12 parts by weight of a polyfunctional reactant; and 4 to 14 parts by weight of the pellet-type second additive (C) using an extruder having 9 or more kneading blocks to provide a sea-island structure that provides a continuous phase (sea), a dispersed phase (islands), additional dispersed phases in the continuous phase (sub-islands in the sea), and individual additional dispersed phases in the dispersed phase (sub-islands in the islands), the continuous phase (sea) comprises polybutylene terephthalate, a copolymer obtained by grafting an unsaturated carboxylic acid or its anhydride or a derivative thereof onto a polyolefin resin, and the polyfunctional reactant; the dispersed phase (islands) are made of the polyarylene ether, the additional dispersed phase (sub-islands in the sea) in the continuous phase consists of the carbon nanotubes and the carbon nanoplates; Each additional dispersed phase (sub-island within the island) in the dispersed phase is comprised of a block copolymer impact modifier. A method for producing a conductive resin composition.

10. A molded article comprising the conductive resin composition according to any one of claims 1 to 8.

11. 11. The molded article of claim 10, wherein the molded article is an electrostatically painted exterior automotive part.

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