KR101672089B1 - Processing method for resin composite and plastic goods obtained from same - Google Patents

Abstract

A step of melt-kneading a thermoplastic resin composition comprising a thermoplastic resin and a carbon nanotube through an extruder to form a resin composite, wherein the screw speed of the extruder is 50% or less of a maximum speed, and the carbon nanotube Wherein I _D / I _G has a value of 0.01 to 2.0, and I _D / I _G indicates the intensity ratio of D peak and G peak in the Raman spectrum of carbon nanotubes in the composition. do.
The processing method can improve the conductivity of the extrusion result by controlling the physical properties and the extrusion conditions of the carbon nanotube as a raw material to suppress the cutting of the carbon nanotubes contained in the thermoplastic resin composition. Therefore, the molded article obtained by using the result of the extrusion has more improved conductivity, and thus can be usefully used for a charging shield, an electric / electronic component housing, and the like.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition,

The present invention relates to a method for producing a resin composite material and a molded article obtained therefrom, and relates to a method for producing a resin composite material which suppresses cutting of carbon nanotubes contained in a thermoplastic resin composition and a molded article having improved conductivity obtained by the method.

Thermoplastic resins, especially high-performance plastics having excellent mechanical properties and heat resistance, are used in various applications. For example, polyamide resins and polyester resins are excellent in balance between mechanical properties and toughness, and thus are used for various electric / electronic parts, machine parts and automobile parts, mainly for injection molding, and poly Butylene terephthalate and polyethylene terephthalate have excellent moldability, heat resistance, mechanical properties and chemical resistance, and are widely used as materials for industrial molded products such as connectors, relays, switches, etc. in automobiles and electric / electronic devices. Further, amorphous resins such as polycarbonate resins are excellent in transparency and dimensional stability, and are used in various fields including various optical materials, electronic devices, office equipment, and automobile parts.

However, electric and electronic parts are required to have antistatic properties such as prevention of static electricity and prevention of dust contamination in order to prevent malfunction and contamination of parts, and electrical conductivity is further required to the existing physical properties, have.

In order to impart such electrical conductivity, surfactants, metal powders, metal fibers and the like have been added. However, these components have low electrical conductivity and deteriorate physical properties such as weak mechanical strength.

Conductive carbon black is often used as a material for imparting conductivity to the resin, but a large amount of carbon black needs to be added to achieve high electrical conductivity, and the structure of the carbon black may be decomposed during the melt mixing process. As a result, the processability of the resin is lowered, and the thermal stability and physical properties are significantly lowered.

Therefore, studies on a carbon nanotube resin composite material in which carbon nanotubes are added in place of conductive carbon black have been actively conducted to improve the conductivity while reducing the amount of the conductive filler added.

A problem to be solved by the present invention is to provide a method for producing a resin composite material capable of suppressing deterioration of physical properties of a thermoplastic resin composition.

Another object to be solved by the present invention is to provide a molded article obtained by the above production method and improved in conductivity.

According to an aspect of the present invention,

A step of melting and kneading a thermoplastic resin composition comprising a thermoplastic resin and a carbon nanotube through an extruder to form a resin composite,

The screw speed of the extruder is 50% or less of the maximum speed,

Wherein I _D / I _G of carbon nanotubes in the composition has a value of 0.01 to 2.0,

Wherein the I _D / I _G represents the intensity ratio of the D peak and the G peak in the Raman spectrum of the carbon nanotube in the composition.

The remaining percentage of carbon nanotubes remaining in the resin composite according to one embodiment may have a value of 1.0% to 20%

The length remaining ratio can be defined according to the following equation:

&Quot; (1) "

(%) = (Length of carbon nanotube remaining in resin composite as a result of extrusion / average length of carbon nanotube in composition used as raw material) X 100

According to one embodiment, the feed rate of the thermoplastic resin composition may be at least 50% of the maximum acceptable feed rate of the extruder.

According to one embodiment, the extruder has at least one flight zone which is distinguished as a kneading disc, the temperature in the barrel of the first flight zone is below the melting temperature of the thermoplastic resin, The temperature in the barrel may be equal to or higher than the melting temperature of the thermoplastic resin.

According to one embodiment, the temperature in the barrel of the first flight zone is below the melting temperature of the thermoplastic resin and may have a graded shape.

According to another aspect of the present invention,

A molded article obtained by the above-mentioned processing method and having improved conductivity is provided.

The method of manufacturing a resin composite material according to an embodiment can control the extrusion conditions of the extruder during the process so as to suppress the cutting of the carbon nanotubes contained in the resin composite material, thereby improving the conductivity of the extruded product.

Therefore, the molded article obtained by using the result of the extrusion has more improved conductivity, and thus can be usefully used for a charging shield, an electric / electronic component housing, and the like.

Hereinafter, the present invention will be described in detail. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

According to an embodiment, the method for producing a resin composite of the present invention includes a step of melting and kneading a thermoplastic resin composition comprising a thermoplastic resin and a carbon nanotube through an extruder, wherein the screw speed of the extruder is 50% And I _D / I _G of the carbon nanotubes in the composition may have a value of 0.01 to 2.0, for example, 0.8 to 2.0.

According to an embodiment of the present invention, carbon nanotubes having an I _D / I _G value within the predetermined range as described above are used as a raw material, and an extrusion process under a more relaxed condition is used. As a result, It is possible to increase the length retention rate of the carbon nanotubes.

The I _D / I _G ratio in the resin composite shows a relative ratio to the intensity of the D peak (D band) and G peak (G band) in the Raman spectrum of the carbon nanotube. In general, Raman spectrum of the carbon nanotube is divided into a lower peak of two of the sp ² bonded graphite castle main peak, i.e. 1,100 to 1,400cm ^-1 and 1,500 to a high peak of 1,700cm ^-1. Near 1,300cm ^-1, for example, the first peak (D- band) of 1,350cm ^-1 is incomplete near to the presence of carbon particles and shows properties of the chaotic wall, 1,600cm ^-1, for example, 1580cm ^-1 The second peak (G-band) represents a continuous form of the carbon-carbon bond (CC), which indicates the characteristics of the crystalline graphite layer of the carbon nanotube. The wavelength value may vary somewhat depending on the wavelength of the laser used in the spectrum measurement.

The intensity ratio (I _D / I _G ) of the D-band peak and the G-band peak can be used to evaluate the degree of disorder or defect of the carbon nanotube. If this ratio is high, it can be evaluated as disordered or defective. It can be estimated that the carbon nanotubes have less defects and higher crystallinity. The defect referred to herein refers to an incomplete portion of the carbon nanotube array caused by unnecessary atoms entering the carbon-carbon bond constituting the carbon nanotube, such as an insufficient amount of atoms entering the carbon nanotube, insufficient carbon atoms, or the like, (lattice defect), whereby the defect portion can be easily cut by the external stimulus.

The intensity of the D-band peak and the G-band peak can be defined, for example, as the height of the X-axis center value in the Raman spectrum or the area of the lower peak, and the height value of the X- .

According to one embodiment, by limiting the I _D / I _G of the carbon nanotubes used as the raw material in the range of 0.01 to 2.0, for example, in the range of 0.01 to 0.7, or 0.01 to 0.5, The average length of the carbon nanotubes can be further improved.

The improved average length can be expressed by the following equation (1).

&Quot; (1) "

(%) = (Average length of carbon nanotubes remaining in the product after extrusion processing / average length of carbon nanotubes used as raw material) X 100

The conductivity of the thermoplastic resin can be increased only by the carbon nanotubes having a smaller content than when the residual ratio is large, which is more advantageous for maintaining the resin properties. According to one embodiment, the residual percentage of the resin composite may have a range of from 1.0% to 20%, for example from 1.0% to 10%.

According to one embodiment, in the case of improving the conductivity by adding carbon nanotubes to a thermoplastic resin, deterioration of the inherent mechanical properties of the thermoplastic resin should be minimized, voids in processing a resin composite or a molded product obtained by processing the composition, It is desirable that there is no problem in processing such as generation, so it is necessary to obtain high conductivity while minimizing the content of carbon nanotubes to be added.

In the present invention, by limiting the I _D / I _G value of carbon nanotubes added to the thermoplastic resin to a predetermined range to selectively use carbon nanotubes having few defects and high crystallinity, they can be cut even when processed in a process such as extrusion The content can be reduced. That is, since the content of the carbon nanotubes cut by the external stimulus generated in the processing is reduced, the residual ratio can be further increased.

As described above, an increase in the percentage of the remaining length corresponds to a more advantageous structure for improving the conductivity of the thermoplastic resin. Since the carbon nanotubes have a network structure in the matrix of the thermoplastic resin, carbon nanotubes having a longer length remaining in the resultant material are more advantageous in forming such a network, and as a result, the frequency of inter-network contact is reduced The contact resistance value is reduced, which contributes to the increase of the conductivity.

According to one embodiment, the residual ratio of the carbon nanotubes may range from 0.5% to 20%, for example, from 0.5% to 10%. In such a range, deterioration of mechanical properties can be suppressed while improving the conductivity of the resultant composite material, and at the same time, workability and the like can be maintained.

The length retention rate of the carbon nanotubes as described above may be affected by an extrusion process, and it is possible to increase the length retention rate by more strictly controlled extrusion conditions.

Generally, an extrusion process is a molding process in which a raw material is fed to an extruder and is pushed out from a structure in the shape of a heating cylinder to convert it into a continuous body having a uniform cross-section, which is a principal molding method for thermoplastic resins and the like. The raw material supplied to the extruder is heated in the cylinder, softened and melted, and transported while being kneaded and compressed by rotation of the screw. The flow of the raw material in the form of a uniform melt is continuously extruded outward from the opening of the mold made into the desired shape, and then subjected to a cooling process to obtain an extrusion result.

In such an extrusion process, the raw material may vary in physical properties while being subjected to a mechanical process under mechanical pressure in a heated state. For example, in the case of carbon nanotubes having a microstructure, mechanical cutting occurs. Therefore, Can have a shape different from that of the carbon nanotube supplied as raw material.

Therefore, it is desirable to carry out the extrusion process while maintaining the physical properties of the raw material. For this purpose, it is necessary to appropriately control the extrusion conditions of the extruder. In the present invention, the rotational speed of the rotating screw mounted on the extruder is controlled to prevent damage to the raw material.

In the present invention, the shape of the extruder is not limited, but it can be distinguished by a single-screw extruder having one screw or a multi-screw extruder having a plurality of screws. In the multi-screw extruder, A twin-screw extruder can be exemplified.

According to one embodiment, the rotation speed of the screw provided in the extruder can be controlled to be 50% or less of the maximum speed of the apparatus, for example, 10 to 40%, in order to suppress the damage of the raw material. The speed of the screw may be, for example, 350 rpm or less, 300 rpm or less, 250 rpm or less, or 200 rpm or less. By controlling the rotation speed of the screw to 350 rpm or less, cutting of the raw material, for example, the carbon nanotube can be suppressed.

If the speed of the screw provided in the extruder is too small, the throughput per unit time lowers to deteriorate the productivity and the kneading performance may be deteriorated. Therefore, the speed of the screw may be 10% or more, Or 70 rpm or more.

The peripheral speed of the screw can be suitably determined by the diameter and the number of revolutions of the screw provided in the extruder. In order to suppress thermal degradation such as a decrease in the molecular weight of the thermoplastic resin, it is usually 1.0 m / sec or less, m / sec or less, or 0.4 m / sec or less. If the peripheral speed of the screw is too small, the dispersing performance of the additive may be deteriorated. Therefore, a range of 0.05 m / sec or more, for example, 0.1 m / sec or more can be used.

The screw of the extruder is composed of a plurality of elements (screw elements) in order to give various functions. Generally, it is composed of a full flight composed mainly of helical threads (flight) for the purpose of carrying resin, a kneading disk for kneading resin, and the like. A reverse flight in which screws are arranged in a direction opposite to the conveying direction of the resin may be used depending on the purpose.

In the present invention, the constitution of these screw elements is not limited, but it is possible to use one having a kneading disc, and one or more of the kneading discs can be used, and the flight zone is distinguished by the kneading disc . In the structure of such an extruder, the total length of the kneading discs may be 20% or less, for example, 15% or less of the entire length of the screw. If the total length of the kneading disc is excessively long, local heat generation due to the shearing of the resin is increased to cause a coloring phenomenon of the thermoplastic resin, or cut off of the carbon nanotubes contained in the raw material may occur to a large extent.

According to an embodiment, if the total length of the kneading discs is too short, the kneading performance described above may be deteriorated. Therefore, the total length of the kneading discs may be in the range of 3% or more, for example, 5% Can be used.

The kneading disc has a forward feed type, an orthogonal type and a reverse feed type with respect to the feeding direction of the resin, and can be appropriately selected depending on the viscosity of the resin used or the required performance.

According to one embodiment, the extruder may comprise a plurality of heating zones and an extrusion die, the plurality of heating zones being distinguishable by the position of the kneading disc. That is, the area where only the flight before the first kneading disk exists can be distinguished as the first flight zone, the flight area between the second kneading disk and the third kneading disk as the second flight zone, and the like. The heating zone according to the present invention may include the first to fifth flight zones, but is not limited thereto.

Such a heating zone can be controlled by a heater provided outside the barrel. Since the heater can be independently controlled, the heating zones can be controlled by individual temperature control methods.

According to one embodiment, the temperature of the first flight zone can be set in a range below the melting temperature of the thermoplastic resin, and a rapid increase in the temperature of the starting material can be prevented in such a range to suppress changes in physical properties and shape . For example, the temperature of the first flight zone may have a graded shape. It is possible to improve the dispersibility of the thermoplastic resin composition through the temperature gradient and improve the mechanical properties such as tensile strength.

As a form of such a temperature gradient, there can be exemplified a case where the temperature gradually increases from the front end portion to the bottom end portion of the first flight zone, that is, in the traveling direction of the raw material. The temperature control of the first flight zone can be controlled by individually controlling the temperature of the heater provided outside the barrel as described above. The maximum temperature of the first flight zone may be in the range of, for example, 180 to 330 ° C, for example, 200 to 325 ° C. The maximum temperature of the first flight zone means the temperature of the lower end of the first flight zone.

According to one embodiment, the temperature of the second flight zone after the first flight zone, that is, the temperature of the second flight zone, may have a range not lower than the melting temperature of the thermoplastic resin. That is, the thermoplastic resin composition that has passed through the first flight zone can be sufficiently melted and kneaded by heating at a temperature higher than the melting temperature of the resin in the following flight zone. The maximum temperature of the heating zone after the first flight zone may have a range of, for example, 180 to 330 ° C, for example, 200 to 325 ° C. The highest temperature of the heating zone after the first flight zone means the highest temperature among all the flight zones existing after the second flight zone.

If the maximum temperature is less than 180 ° C, sufficient kneading is difficult to obtain, and if it exceeds 330 ° C, thermal decomposition of the thermoplastic resin may occur.

According to one embodiment, the screw included in the extruder has a ratio of the screw length L and the screw diameter D (L / D) of 30 or more, for example, 50 to 200, or 80 to 200 . Here, the screw length means the length from the upstream edge portion of the screw segment at the position where the resin is fed to the front end of the screw.

According to one embodiment, when the thermoplastic resin composition is extruded using a twin screw extruder having an L / D of 50 or more, the extrusion amount is 0.01 kg / h or more, for example, 0.05 kg / h to 1 kg / h, or from 0.08 to 0.5 kg / h. Here, the extrusion amount means the weight (kg) per hour of the melt-kneaded material discharged from a twin screw extruder having a screw diameter of 41 mm.

According to one embodiment, the residence time in the extrusion may range from 1 to 30 minutes, for example from 1.5 to 25 minutes. This residence time is a value representing the average of the residence time up to the discharge time after the supply of the raw material to the extruder. The residence time is defined as the time from the position of the bottom of the screw to which the raw material is supplied to the point of time when it is discharged from the discharge port of the extruder in a normal melt-kneading state in which the melt-kneaded product is adjusted to a predetermined extrusion amount.

When a twin-screw extruder is used as the extruder, the screw of the twin-screw extruder is not particularly limited and may be a fully meshed type, an incomplete meshing type, or a non-meshing type screw. From the viewpoints of kneading property and reactivity, a fully engageable screw is preferable. The rotation direction of the screw may be either the same direction or the opposite direction, but it is preferable that the screw is rotated in the same direction from the viewpoint of kneading property and reactivity. As the screw, it is most preferable to use the complete rotation type of rotation in the same direction.

According to one embodiment, an inert gas may be introduced and melt-kneaded in the raw material input portion to suppress thermal deterioration of the resin in the extrusion process. As the inert gas at this time, nitrogen and the like may be exemplified.

Examples of the kneading method using the extruder include a method of batchwise kneading a thermoplastic resin and a carbon nanotube, a method of preparing a resin composition (master pellet) containing a high concentration of carbon nanotubes in a thermoplastic resin, (Master pellet method) in which the above-mentioned resin composition and carbon nanotube are added and melted and kneaded, and any kneading method may be used. As another method, a method of melt kneading by feeding a thermoplastic resin from an extruder side and feeding a carbon nanotube to an extruder using a side feeder can be exemplified in order to suppress breakage of the carbon nanotube.

The carbon nanotube (CNT) is a material in which carbon atoms arranged in a hexagonal shape form a tube, and has a diameter of about 1 to 100 nm. Carbon nanotubes exhibit non-conductive, conductive, or semiconducting properties due to their unique chirality. They have strong tensile strengths greater than about 100 times greater than steel due to their strong covalent bonds, and are excellent in flexibility and elasticity, It is chemically stable.

Examples of carbon nanotubes include single-walled carbon nanotubes (SWCNTs) composed of one layer and having a diameter of about 1 nm, double-walled carbon nanotubes composed of two layers and having a diameter of about 1.4 to 3 nm walled carbon nanotubes (DWCNTs), and multi-walled carbon nanotubes (MWCNTs) composed of a plurality of three or more layers and having a diameter of about 5 to 100 nm, Can be used without limitation.

As used herein, the term "bundle" refers to a bundle or rope shape in which a plurality of carbon nanotubes are arranged or intertwined in parallel, unless otherwise specified. The term 'non-bundle or entangled type' means a form without any uniform shape such as a bundle or a rope shape.

The bundle-type carbon nanotubes basically have a shape in which a plurality of carbon nanotube strands are gathered together to form a bundle, and the plurality of strands have a straight shape, a curved shape, or a mixture thereof. The bundle-type carbon nanotubes may also have a linear, curved or mixed form. According to one embodiment, such a bundle of carbon nanotubes may have a thickness of 50 nm to 100 탆.

According to one embodiment, the average diameter of the carbon nanotube strands may be, for example, 1 nm to 40 nm.

According to one embodiment, the bundle-type carbon nanotubes used as a raw material have an average length of about 1 탆 or more, for example, 1 탆 to 10,000 탆, or 5 탆 to 1,000 탆, or 10 탆 to 300 탆 And the thickness may range from 10 nm to 1,000 탆. The carbon nanotubes in the form of bundles having an average length and a thickness in this range are more advantageous structures for improving the conductivity of the thermoplastic resin-containing composite material. Since the carbon nanotubes have a network structure in the matrix of the thermoplastic resin-containing composite material, the long carbon nanotubes are more advantageous in the formation of such a network, and as a result, the frequency of inter-network contact is reduced, The value is reduced, which contributes to the increase of the conductivity.

According to one embodiment, the carbon nanotubes used in the production of the thermoplastic resin-containing composite material have a relatively high bulk density, which may be more advantageous in improving the conductivity of the composite material. The bulk density of the carbon nanotubes may range from 1 to 1,000 kg / m ³ , for example, from 80 to 250 kg / m ³ .

As used herein, the term "bulk density" means the apparent density of the carbon nanotubes in the raw material state, and the weight of the carbon nanotubes can be expressed as a value divided by the volume.

According to one embodiment, the average length of the carbon nanotubes can be measured by a scanning electron microscope (SEM) or a transmission electron microscope (TEM) photograph. That is, after obtaining photographs of the powdered carbon nanotubes as a raw material through these measuring devices, they were analyzed through an image analyzer, for example, Scandium 5.1 (Olympus soft Imaging Solutions GmbH, Germany) Can be obtained.

In the case of the carbon nanotubes contained in the melt-kneaded product or the molded product, the resin solids are dissolved in an organic solvent such as acetone, ethanol, n-hexane, chloroform, p-xylene, 1-butanol, -Trichlorobenzene, and dodecane, and then the resultant is measured by SEM or TEM using this dispersion, and the result is analyzed using the image analyzer to obtain an average length and a distribution state.

According to one embodiment, the bundle-type carbon nanotubes may be used in an amount of 0.01 to 20 parts by weight, or 0.1 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin. In this range, sufficient conductivity can be obtained while maintaining mechanical properties.

According to one embodiment, the carbon nanotube-containing thermoplastic resin composition may be used in combination with a flame retardant, an impact modifier, a flame retardant, a flame retardant, a flame retardant, a lubricant, a plasticizer, a heat stabilizer, a dripping inhibitor, an antioxidant, a compatibilizer, And an anti-dripping agent. The content of the additive may be 0.1 to 10 parts by weight based on 100 parts by weight of the thermoplastic resin. The specific types of these additives are well known in the art, and examples that can be used in the compositions of the present invention can be appropriately selected by those skilled in the art.

According to one embodiment, the thermoplastic resin can be used without limitation as long as it is used in the art, and examples thereof include a polycarbonate resin, a polypropylene resin, a polyamide resin, an aramid resin, an aromatic polyester resin, a polyolefin resin, A polyphenylene ether resin, a polyphenylene ether resin, a polyphenylene sulfide resin, a polyether sulfone resin, a polyarylene resin, a cycloolefin resin, a polyetherimide resin, a polyacetal resin, a polyvinyl acetal resin, A resin, a polyether ketone resin, a polyether ether ketone resin, a polyaryl ketone resin, a polyether nitrile resin, a liquid crystal resin, a polybenzimidazole resin, a polyparasporic acid resin, an aromatic alkenyl compound, a methacrylic acid ester, And a vinyl cyanide compound A vinyl polymer or copolymer resin obtained by polymerization or copolymerization of one or more vinyl monomers, a diene-aromatic alkenyl compound copolymer resin, a vinyl cyanide-diene-aromatic alkenyl compound copolymer resin, an aromatic alkenyl compound- Vinyl chloride-vinylidene chloride copolymer resin, vinyl cyanide-vinyl-N-phenylmaleimide copolymer resin, vinyl cyanide- (ethylene-diene-propylene (EPDM)) -aromatic alkenyl compound copolymer resin, polyolefin, vinyl chloride resin and chlorinated vinyl chloride resin At least one can be used. The specific types of these resins are well known in the art and can be suitably selected by those skilled in the art.

The polyolefin resin may be, for example, polypropylene, polyethylene, polybutylene, and poly (4-methyl-1-pentene), and combinations thereof, but is not limited thereto. In one embodiment, the polyolefins include polypropylene homopolymers (e.g., atactic polypropylene, isotactic polypropylene, and syndiotactic polypropylene), polypropylene copolymers (e.g., For example, polypropylene random copolymers), and mixtures thereof. Suitable polypropylene copolymers include but are not limited to the presence of comonomers selected from the group consisting of ethylene, but-1-ene (i.e., 1-butene), and hex-1-ene Lt; RTI ID = 0.0 > of propylene. ≪ / RTI > In such polypropylene random copolymers, the comonomer may be present in any suitable amount, but is typically present in an amount of up to about 10 wt% (e.g., from about 1 to about 7 wt%, or from about 1 to about 4.5 wt%) Can exist.

The polyester resin is a homopolyester or a copolymer polyester which is a polycondensation product of a dicarboxylic acid component skeleton and a diol component skeleton. Examples of the homopolyester include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, . Particularly, since polyethylene terephthalate is inexpensive, it can be used in a wide variety of applications. The copolymer polyester is defined as a polycondensate comprising at least three or more components selected from the following components having a dicarboxylic acid skeleton and a component having a diol skeleton. Examples of the component having a dicarboxylic acid skeleton include terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, -Diphenyl dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, adipic acid, sebacic acid, dimeric acid, cyclohexanedicarboxylic acid and ester derivatives thereof. Examples of the component having a glycol skeleton include ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, diethylene glycol, polyalkylene glycol, 2,2- 4'-p-hydroxyethoxyphenyl) propane, isosorbate, 1,4-cyclohexanedimethanol, spiroglycol and the like.

As the polyamide resin, nylon resin, nylon copolymer resin, and mixtures thereof can be used. Examples of the nylon resin include polyamide-6 (nylon 6) obtained by ring-opening polymerization of a lactam such as? -Caprolactam or? -Dodecaractam commonly known in the art; Nylon polymers obtained from amino acids such as aminocaproic acid, 11-amino undecanoic acid, and 12-aminododecanoic acid; But are not limited to, ethylenediamine, tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, , Metaxylenediamine, para-xylenediamine, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis Aminocyclohexyl) methane, bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperidine, etc. Alicyclic or aromatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, terephthalic acid, 2-chloroterephthalic acid, and 2-methylterephthalic acid, etc. A nylon polymer obtainable from the polymerization of Copolymers or mixtures thereof may be used. Examples of the nylon copolymer include copolymers of polycaprolactam (nylon 6) and polyhexamethylene sebacamide (nylon 6,10), copolymers of polycaprolactam (nylon 6) and polyhexamethyleneadipamide (nylon 66) And copolymers of polycaprolactam (nylon 6) and polylauryl lactam (nylon 12).

The polycarbonate resin may be prepared by reacting a diphenol with phosgene, a halogen formate, a carbonic ester, or a combination thereof. Specific examples of the diphenols include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) propane (also referred to as bisphenol- (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis Bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis Bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) Ether, and the like. Of these, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane or 1,1- Cyclohexane may be used, and more preferably 2,2-bis (4-hydroxyphenyl) propane may be used.

The polycarbonate resin may be a mixture of copolymers prepared from two or more diphenols. The polycarbonate resin may be a linear polycarbonate resin, a branched polycarbonate resin, or a polyester carbonate copolymer resin.

Examples of the linear polycarbonate resin include a bisphenol-A polycarbonate resin and the like. Examples of the branched polycarbonate resin include those prepared by reacting a polyfunctional aromatic compound such as trimellitic anhydride, trimellitic acid and the like with a diphenol and a carbonate. The polyfunctional aromatic compound may be contained in an amount of 0.05 to 2 mol% based on the total amount of the branched polycarbonate resin. Examples of the polyester carbonate copolymer resin include those prepared by reacting a bifunctional carboxylic acid with a diphenol and a carbonate. As the carbonate, diaryl carbonate such as diphenyl carbonate, ethylene carbonate and the like can be used.

Examples of the cycloolefin-based polymer include a norbornene polymer, a monocyclic olefin polymer, a cyclic conjugated diene polymer, a vinyl alicyclic hydrocarbon polymer, and hydrides thereof. Specific examples thereof include APEL (an ethylene-cycloolefin copolymer produced by Mitsui Chemicals, Inc.), Aton (a norbornene-based polymer manufactured by JSR Corporation), and Zeonoa (a norbornene-based polymer manufactured by Nippon Zeon).

A composite material having a shape such as pellet or film can be produced through the above-described processing method of the thermoplastic resin composition containing a carbon nanotube.

The carbon nanotube-thermoplastic composite material having sufficient electrical properties can be obtained even when a small amount of carbon nanotubes are added while the mechanical strength of the composite material obtained through the above method is not lowered, .

The composite material according to one embodiment can be molded by any known method such as injection molding, blow molding, press molding, and spinning, and can be processed into various molded articles. As the molded article, it can be used as an injection molded article, an extrusion molded article, a blow molded article, a film, a sheet, a fiber and the like.

As a method for producing the film, a known melt film-forming method can be employed. For example, raw materials are melted in a single-screw or twin-screw extruder, then extruded from a film die, and cooled on a cooling drum to form an unstretched film Or a uniaxial stretching method and a biaxial stretching method in which the film produced in this way is appropriately stretched in the transverse direction by a transverse stretching device called a roller type longitudinal stretching device and a tenter .

The fibers can be used as various kinds of fibers such as unstretched fibers, drawn fibers, primary rolled fibers and the like. As a method of producing fibers using the resin composition, a known melt spinning method can be applied. For example, Is extruded from a spinneret through a polymer flow line switcher or filtration layer provided at the tip of the extruder, and is then cooled, , Stretching, and heat setting may be employed.

The average length of the carbon nanotubes remaining in the composite or the molded product may be in the range of 0.8 μm to 1,000 μm.

In particular, the composite material of the present invention can be processed into a molded article such as a charge shielding material, an electric / electronic product housing, and an electric / electronic part, taking advantage of its excellent conductivity and excellent mechanical properties.

According to one embodiment, the various molded articles can be used for various purposes such as automobile parts, electric parts, and building members. Specific applications include airflow meters, air pumps, thermostat housings, engine mounts, ignition bobbins, ignition cases, clutch bobbins, sensor housings, idle speed control valves, vacuum switching valves, ECU housings, Pump case, Inhibitor switch, Rotary sensor, Accelerometer, Distributor cap, Coil base, ABS actuator case, Radiator tank top and bottom, Cooling fan, Fan shroud, Engine cover, Cylinder head cover, Oil cap , Oil pan, oil filter, fuel cap, fuel strainer, distributor cap, vapor canister housing, air cleaner housing, timing belt cover, brake booster parts, various cases, various tubes, various tanks, various hoses Under-hood parts for automobiles such as clips, various valves, various pipes, etc. Torque control Wheel rails, fenders, fenders, garnishes, knobs, and other parts, such as seatbelt components, seatbelt components, register blades, wash lever, wind regulator handle, knob of wind regulator handle, passing light lever, sun visor bracket, Automotive exterior parts such as bumper, door mirror stay, spoiler, hood louver, wheel cover, wheel cap, grille apron cover frame, lamp reflector, lamp bezel, door handle, wire harness connector, SMJ connector, PCB Relay case, coil bobbins, optical pickup chassis, motor case, notebook PC housings and internal parts, LED display housings and internal parts, printer housings and internal parts, mobile phones, etc., for various automobile connectors, connectors and door grommet connectors. , A portable terminal housing and internal parts such as a mobile PC, a portable mobile, a recording medium (CD, DVD, PD, FDD, etc.) There may be mentioned o electrical and electronic components, represented by the housing and internal components, a housing and inner parts of copying machine, facsimile housings and internal parts of the parabolic antenna and the like.

In addition, it is also possible to use a VTR component, a television component, an iron, a hair dryer, an electric rice cooker component, a microwave component, an acoustic component, , An optical recording medium such as a CD-R, a CD-RW, a DVD-ROM, a DVD-R, a DVD-RW, a DVD-RAM, Examples of household electrical appliances parts represented by parts and the like.

In addition, a housing, an internal part, various gears, various cases, a sensor, an LEP lamp, a connector, a socket, a resistor, a relay case, a switch, a coil bobbin, a capacitor, a variable capacitor, The present invention relates to a magnetic head base, a power module, a semiconductor, a liquid crystal, an FDD carriage, an FDD chassis, a motor, a motor, a case, an optical pickup, an oscillator, various terminal boards, transformers, plugs, printed wiring boards, tuners, Such as a brush holder, a transformer member, a coil bobbin, and the like, as well as various automotive connectors such as a wire harness connector, an SMJ connector, a PCB connector, and a door gray connector.

On the other hand, since the molded article has improved conductivity, it can be used as an electromagnetic wave shielding body by absorbing electromagnetic waves. The electromagnetic wave shielding material absorbs and extinguishes electromagnetic waves, and thus exhibits an improved performance in electromagnetic wave absorbing ability.

Further, the thermoplastic resin-containing composite material of the present invention and the molded article composed of the composite material can be recycled. For example, the resin composition obtained by pulverizing the composite material and the molded product, preferably in the form of a powder, and then adding an additive, if necessary, may be used in the same manner as the composite material of the present invention, and may be formed into a molded product.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

Example

The following components and additives were used in the following examples and comparative examples.

(a) a polyamide resin

LUMID GP-1000B of LG Chem Co., Ltd. was used.

(b) Carbon nanotubes

Carbon nanotubes having various lengths and I _D / I _G were used.

Example 1

The raw materials were mixed in the composition shown in Table 1 below, and the mixture was fed into a feeding portion of a twin-screw extruder. As a twin-screw extruder, a twin-screw extruder (Toshiba Machine Co., Ltd., TEM-41SS-22 / 1V) with a screw diameter of 41 mm and a screw of two screw threads and a screw of L / did. The extruder had a kneading disk located at a specific position. And a melt flow rate of 50% or less of the maximum rotational speed of the extruder at 200 rpm to discharge the stranded molten resin from the discharge port (L / D = 100). The molten resin on the discharged strand was cooled by passing through a cooling bath and cut while being pulled out from the pelletizer to obtain a pellet sample of the melt-kneaded product.

The prepared pellets were injected from an injection machine at an injection temperature of 280 캜 to prepare specimens. The prepared specimens were allowed to stand at 23 DEG C and 50% relative humidity for 48 hours, and physical properties and conductivities were measured according to ASTM standard, which is a standard measurement method in the United States, and are shown in Table 2 below.

Example 2

The same procedure as in Example 1 was carried out except that the raw materials were mixed in the composition shown in the following Table 1 and the temperature of the first flight zone was changed in Example 1, And physical properties and conductivities thereof are shown in Table 2 below.

Example 3

The raw materials were mixed in the composition shown in Table 1 below, and the same processes as in Example 1 were carried out to prepare specimens. The properties and conductivity of the specimens were measured in the same manner as described in Table 2 below.

Example 4

The properties and conductivity were measured in the same manner as in Example 2, and the results are shown in Table 2 below.

Comparative Example 1

The same procedure as in Example 1 was carried out except that raw materials were mixed in the composition shown in Table 1 and the rotation speed of the screw was controlled at 380 rpm in Example 1 to prepare a specimen , Physical properties and conductivity were measured according to the same method and are shown in Table 2 below.

Comparative Example 2

The same procedure as in Example 2 was carried out except that raw materials were mixed in the composition shown in the following Table 1 and the rotational speed of the screw was controlled at 380 rpm in Example 2, And physical properties and conductivities thereof are shown in Table 2 below.

Comparative Example 3

The same procedure as in Example 3 was carried out except that raw materials were mixed in the composition shown in the following Table 1 and the rotation speed of the screw was controlled at 380 rpm in Example 3, , Physical properties and conductivity were measured according to the same method and are shown in Table 2 below.

Comparative Example 4

The same procedure as in Example 4 was carried out except that raw materials were mixed in the composition shown in Table 1 below and the rotation speed of the screw was controlled at 380 rpm in Example 4, And physical properties and conductivities thereof are shown in Table 2 below.

division Carbon nanotubes (raw materials) I _D / I _G Average length (탆) Example 1 0.9 150 Example 2 0.9 150 Example 3 1.3 175 Example 4 1.3 175 Comparative Example 1 0.9 150 Comparative Example 2 0.9 150 Comparative Example 3 1.3 175 Comparative Example 4 1.3 175

Experimental Example

The properties of the specimens prepared in Examples 1 to 4 and Comparative Examples 1 to 4 were measured by the following methods, and the results are shown in Table 2 below.

- The tensile strength

The tensile strength and the tensile elastic modulus of the specimens obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated according to ASTM D638 standard with a thickness of 3.2 mm.

- Surface resistivity (Ω / cm)

The surface resistance of the specimens was measured according to ASTM D257 using the specimens obtained in Examples 1 to 4 and Comparative Examples 1 to 4 using SRM-100 manufactured by PINION.

- remaining carbon nanotube length

The average length of the remaining carbon nanotubes in the composite material was measured by dispersing the pellets obtained in Examples 1 to 4 and Comparative Examples 1 to 4 in chloroform to obtain a dispersion liquid having a concentration of 0.1 g / l, and then measuring the TEM (Libra 120, Carl Zeiss Gmbh, Germany) images were analyzed with SCANDIUM 5.1 (Olympus Soft Imaging Solutions GmbH).

division Example Comparative Example One 2 3 4 One 2 3 4 Surface resistivity
(Ω / cm) 1.0X10 ⁸ 1.0X10 ⁸ 1.0X10 ⁹ 1.0X10 ⁹ 1.0X10 ¹⁰ 1.0X10 ¹⁰ 1.0X10 ¹¹ 1.0X10 ¹¹ The tensile strength
(MPa) 92 90 88 90 85 80 82 80 Carbon nanotubes
Remaining length (nm) 3,000 2,800 2,000 1,900 1,200 1,171 650 580 Length remaining rate
(%) 2.0 1.8 1.1 1.0 0.8 0.7 0.4 0.3

As shown in Table 2 above, the composite material obtained according to the above Examples 1 to 4 controls the extrusion conditions of the extrusion process while using carbon nanotubes having few defects as a raw material, so that as the remaining length of the carbon nanotubes increases, And the tensile strength was improved by improving the dispersibility, especially by using the extrusion conditions using the temperature gradient conditions.

Claims (18)

Melting and kneading a thermoplastic resin composition comprising a thermoplastic resin and a carbon nanotube through an extruder to form a resin composite,
The screw speed of the extruder is 50% or less of the maximum speed,
The screw included in the extruder has a screw length (L) and a screw diameter (D) ratio (L / D) of 80 to 200,
Wherein the carbon nanotube raw material has an average length of 150 to 10,000 占 퐉,
Wherein I _D / I _G of carbon nanotubes in the composition has a value of 0.01 to 2.0,
Wherein I _D / I _G represents the intensity ratio of the D peak and the G peak in the Raman spectrum of the carbon nanotube in the composition,
The remaining carbon nanotubes remaining in the resin composite have a length retention rate of 1.0% to 20% and the remaining length ratio is as shown in the following formula 1:
&Quot; (1) "
(%) = (Average length of carbon nanotubes remaining in the resin composite resulting from extrusion / average length of carbon nanotubes in the composition used as raw material) X 100,
And the average length of the carbon nanotubes remaining in the resin composite material is from 0.8 mu m to 1,000 mu m. delete delete The method of claim 1, wherein
Wherein I _D / I _G of carbon nanotubes in the composition is 0.8 to 2.0. The method according to claim 1,
Wherein the feed rate of the thermoplastic resin composition is 50% or more of a maximum allowable feed rate of the extruder. The method according to claim 1,
Wherein the extruder has at least one flight zone which is distinguished by a kneading disk and the temperature in the barrel of the first flight zone is below the melting temperature of the thermoplastic resin and the temperature in the barrel after the first flight zone is equal to or higher than the melting temperature of the thermoplastic resin Wherein the resin composite is produced by a method comprising the steps of: The method according to claim 6,
Wherein a temperature in the barrel of the first flight zone is equal to or lower than a melting temperature of the thermoplastic resin and a temperature gradually increases in a direction of progress of the raw material. The method according to claim 1,
Wherein the extruder is a twin screw extruder having two screws. The method according to claim 1,
Wherein the extruder has a flight zone divided by a kneading disk. The method according to claim 1,
Wherein the content of the carbon nanotubes is 0.01 to 20 parts by weight based on 100 parts by weight of the thermoplastic resin. The method according to claim 1,
Wherein at least one member selected from the group consisting of a flame retardant, an impact modifier, a flame retardant aid, a lubricant, a plasticizer, a heat stabilizer, an antistatic agent, an antioxidant, a compatibilizing agent, a light stabilizer, a pigment, a dye, Further comprising an additive to be selected. The method according to claim 1,
Wherein the thermoplastic resin is selected from the group consisting of polycarbonate resin, polyamide resin, aramid resin, aromatic polyester resin, polyolefin resin, polyester carbonate resin, polyphenylene ether resin, polyphenylenesulfide resin, polysulfone resin, polyether sulfone resin, poly A polyether ketone resin, a polyether ketone resin, a polyether nitrile resin, a liquid crystal resin, a polyetherketone resin, a polyvinyl acetal resin, a polyketone resin, a polyether ketone resin, Based polymer obtained by polymerizing or copolymerizing at least one vinyl monomer selected from the group consisting of a polybenzimidazole resin, a polypararbasanic acid resin, an aromatic alkenyl compound, a methacrylic acid ester, an acrylic acid ester, and a vinyl cyanide compound Or a copolymer resin, a diene-aromatic compound (Ethylene-diene-propylene (EPDM) copolymer) resin, a vinyl cyanide-diene-aromatic alkenyl compound copolymer resin, an aromatic alkenyl compound-diene-vinylidene cyanide-N-phenylmaleimide copolymer resin, ) -Aromatic alkenyl compound copolymer resin, a polyolefin, a vinyl chloride resin, and a chlorinated vinyl chloride resin. A composite material obtained by the production method according to any one of claims 1 to 12. A molded article comprising the composite according to claim 13. A molded article obtained by processing the composite material according to claim 13. 16. The method of claim 15,
Wherein the processing step is an extrusion step, an injection step, or an extrusion / injection step. 15. The method of claim 14,
And the average length of the carbon nanotubes remaining in the molded article is from 0.8 mu m to 1,000 mu m. 15. The method of claim 14,
Charging shields, electrical / electronic product housings or electrical / electronic parts.