JP2017145414A - Method for producing conductive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a conductive resin composition capable of preventing deterioration of mechanical characteristics of an olefin-based polymer resin and imparting excellent electric conductivity, and to provide a method for producing a fuel tank or hose for a vehicle.SOLUTION: There are provided: a method for producing a conductive resin composition which comprises a step of producing a master batch containing a high content of conductive filler by mixing and compressing (extruding) carbon nanotubes (CNT) and a first olefin-based polymer resin, and then mixing the master batch with a second olefin-based polymer resin of the same kind as or a different kind from the first olefin-based polymer resin; and a method for producing a fuel tank or hose for a vehicle using the composition. There is provided a method for producing a conductive resin composition, in which the content of CNT contained in the master batch is 10 to 30 wt.%, and the content of CNT contained in the conductive resin composition is 0.1 to 10 wt.%. There is provided a method for producing a conductive resin in which the production of a master batch is carried out at a compression (extrusion) rate of 10 to 500 kg/hr at 180 to 300°C.SELECTED DRAWING: None

Description

Cross-citation with related application This application claims the benefit of priority based on Korean Patent Application No. 10-2016-0020000 filed on Feb. 19, 2016, and was disclosed in the Korean patent application literature All the contents are incorporated as part of this specification.

TECHNICAL FIELD The present invention relates to a method for producing a conductive resin composition. More specifically, the present invention relates to a conductive material capable of realizing a balanced trade-off between electrical conductivity and mechanical properties by relaxing the tradeoff. The present invention relates to a method for producing a resin composition.

  A thermoplastic resin refers to a plastic (resin) that softens when heated and exhibits plasticity and solidifies when cooled. Such thermoplastic resins are excellent in processability and moldability and are widely applied to various daily necessities, OA equipment, electrical / electronic products, vehicle parts and the like.

  In addition, attempts have been continuously made to add special properties and use them as high-value-added materials depending on the types and characteristics of products in which such thermoplastic resins are used.

  In particular, when a thermoplastic resin is applied to a field where friction between resin products or other materials occurs, it is necessary to impart electrical conductivity to the thermoplastic resin because the product is damaged and contaminated by a charging phenomenon. is there.

  Thus, conductive fillers such as carbon nanotubes, carbon black, graphite, carbon fiber, metal powder, metal-coated inorganic powder, or metal fiber have been conventionally used to impart electrical conductivity to thermoplastic resins.

  However, in order to derive a meaningful result for imparting electrical conductivity, it is necessary to add about 10 to 20% by weight or more of a conductive filler relative to the thermoplastic resin. It leads to a decrease in inherent mechanical properties such as impact resistance, elongation rate, and abrasion resistance.

  In particular, in fields where electrical conductivity and mechanical properties are required for thermoplastic resins at the same time, for example, fields such as fuel tanks or fuel hoses for vehicles, there is a limit to commercialization of products due to the problem of maintaining the balance between the two. Occur.

  In addition, when it is required to impart electrical conductivity to a high viscosity thermoplastic resin, there is a problem that sufficient electrical conductivity due to the addition of a conductive filler is not realized due to the properties of the thermoplastic resin.

  Provided is a conductive resin composition capable of realizing excellent electrical conductivity while preventing deterioration of mechanical properties of thermoplastic resins, particularly high viscosity thermoplastic resins.

  One aspect of the present invention is: (a) a step of producing a master batch by compressing (extruding) carbon nanotubes (CNT) and a first olefin polymer resin; and (b) the master batch and the second olefin system. A method for producing a conductive resin composition comprising the steps of: mixing a polymer resin.

  In one embodiment, step (a) may be performed at a temperature of 180 to 300 ° C.

  In one embodiment, in the step (a), the compression (extruding) may be performed at a speed of 10 to 500 kg / hr.

  In one embodiment, the content of carbon nanotubes included in the master batch may be 10 to 30% by weight.

  In one embodiment, the content of carbon nanotubes contained in the conductive resin composition may be 0.1 to 10% by weight.

  In one embodiment, the apparent density of the carbon nanotubes may be 0.01 to 0.2 g / ml.

  In one embodiment, each of the first and second olefin polymer resins is a group consisting of high density polyethylene, low density polyethylene, linear low density polyethylene, polyethylene copolymer, polypropylene, and a mixture of two or more thereof. It can be one selected.

  In one embodiment, the polyethylene copolymer is selected from the group consisting of ethylene vinyl acetate (copolymer), ethylene butyl acrylate (copolymer), ethylene ethyl acrylate (copolymer), and a mixture of two or more thereof. It can be one selected.

  In one embodiment, the first olefin polymer resin may be a mixture of polyethylene and ethylene vinyl acetate (copolymer) in a weight ratio of 2 to 3: 1.

  In one embodiment, prior to step (b), the method may further include pelletizing the product of step (a).

  Another aspect of the present invention provides a method for manufacturing a fuel tank for a vehicle, further comprising (c) a step of molding the conductive resin composition after the step (b).

  According to still another aspect of the present invention, there is provided a method for manufacturing a fuel hose for a vehicle, further comprising (c) a step of molding the conductive resin composition after the step (b).

  According to one aspect of the present invention, a conductive batch and a first olefin polymer resin are mixed to produce a masterbatch containing a high content of conductive filler, which is the same as the first olefin polymer resin. By mixing with a second olefin polymer resin that is different or different, the mechanical properties of the olefin polymer resin can be prevented from being lowered and excellent electrical conductivity can be imparted.

  The effects of the present invention are not limited to the effects described above, but include all effects that can be inferred from the detailed description of the present invention or the structure of the invention described in the claims.

FIG. 1 is a view showing a method for producing a conductive resin composition according to one aspect of the present invention. FIG. 2 is a graph showing the surface resistance values of molded articles produced using the resin compositions according to Examples and Comparative Examples of the present invention. FIG. 3 is a graph showing impact strength values of molded articles produced using the resin compositions according to the examples and comparative examples of the present invention. FIG. 4 is a graph showing the tensile strength values of molded articles manufactured using the resin compositions according to Examples and Comparative Examples of the present invention. FIG. 5 is a graph showing elongation values of molded articles manufactured using the resin compositions according to Examples and Comparative Examples of the present invention.

  Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention can be embodied in various forms. Therefore, the present invention is not limited to the embodiment described here.

  Throughout the specification, the term “comprising” a part includes a predetermined component does not exclude other components but includes other components unless specifically stated to the contrary (limitation). Means that.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a view showing a method for producing a conductive resin composition according to one aspect of the present invention. Referring to FIG. 1, a method for producing a conductive resin composition according to an aspect of the present invention includes: (a) a step of producing a master batch by compressing (extruding) carbon nanotubes and a first olefin polymer resin. And (b) mixing the masterbatch with a second olefin polymer resin.

  The conductive resin composition can be basically composed of a polymer resin having a certain level of mechanical properties and moldability, and a conductive material capable of imparting conductivity to the resin, such as metals and other inorganic materials. In order to manufacture such a conductive resin composition, a process for mixing the polymer resin and the conductive material is required (entrained).

  Conventionally, a technique for increasing the content of the conductive material in order to improve the electrical conductivity of the conductive resin composition has been proposed. However, when the content of the same kind of conductive material, in particular, the carbon nanotube is increased to a certain level or more, there is a problem that not only the mechanical properties of the resin itself but also workability and workability are deteriorated. In order to eliminate this, the effect of imparting conductivity is weak compared to carbon nanotubes, but the total content of conductive substances in the conductive resin composition can be reduced by using carbon black with excellent processability and workability. Attempts were made to increase it.

  However, such a method is only adjusted so that the kind and content of the conductive material are different, and is common in that the mixing of the resin conductive material is performed by a single process.

  On the other hand, in the step (a), the carbon nanotubes which are conductive fillers and the first olefin polymer resin are mixed and compressed (extruded) to produce a high concentration carbon nanotube master batch.

  As used herein, the term “masterbatch” is a pre-dispersed high concentration additive in the production of a resin composition. The dispersibility of the carbon nanotubes in the molecular resin can be improved. Thereby, uniform electrical conductivity can be imparted to the entire region of the conductive resin composition.

  At this time, the master batch may be manufactured in a sphere shape, a pellet shape, or the like. However, it is possible to improve the dispersibility of the carbon nanotubes by being blended with a thermoplastic resin in a later stage. For example, it can be manufactured without limitation on its form.

  The carbon nanotube is a substance for imparting electrical conductivity to a thermoplastic polymer resin, particularly an olefin polymer resin, which is a non-conductor, and is formed by molding a resin composition to which the carbon nanotube is added. Electrical conductivity can be improved by reducing the surface resistance of the manufactured plastic substrate.

  Examples of the method for synthesizing the carbon nanotube include an arc discharge method (Arc-discharge), a thermal decomposition method (Pyrolysis), a laser deposition method (Laser vaporization), a plasma chemical vapor deposition method (Plasma chemical vapor deposition), and a thermochemical vapor deposition method. Although there is a phase vapor deposition method, all carbon nanotubes manufactured without limitation on the synthesis method can be used.

  The carbon nanotubes may be single walled carbon nanotubes, double walled carbon nanotubes, multi-walled carbon nanotubes, or multi walled carbon nanotubes depending on the number of walls. A carbon nanofiber in the form of a hollow tube in which a large number of cone-shaped graphenes are laminated (cup-stacked carbon nanofiber), and a mixture of two or more of these, preferably May be a multi-walled carbon nanotube excellent in manufacturing ease and economy, but is not limited thereto.

  On the other hand, the olefin polymer resin used as the base material of the masterbatch has few changes in physical properties in a relatively wide temperature range among thermoplastic resins, and is excellent in moldability, weather resistance, chemical resistance, and the like.

  The first olefin polymer resin is one selected from the group consisting of high density polyethylene, low density polyethylene, linear low density polyethylene, polyethylene copolymer, polypropylene, and a mixture of two or more thereof. Preferably, it is a polyethylene series, and more preferably, it can be high-density polyethylene, but is not limited thereto.

  The polyethylene copolymer is selected from the group consisting of ethylene vinyl acetate (copolymer), ethylene butyl acrylate (copolymer), ethylene ethyl acrylate (copolymer), and a mixture of two or more thereof. However, the present invention is not limited to this.

  That is, the first olefin polymer resin may be a single polymer obtained by polymerizing the same type monomers, a copolymer obtained by polymerizing different types of monomers, or a mixture thereof. The copolymer may be an alternating copolymer, a random copolymer, a block copolymer, or a graft copolymer without limitation of a polymerization form. obtain.

  In particular, when a different olefin polymer resin mixture is used in the production of the masterbatch as compared with the case where the same olefin polymer resin is used, the electrical conductivity and mechanical properties of the resin composition are affected by the interaction between them. The balance of physical properties can be maintained even better.

  Specifically, the first olefin polymer resin is a mixture of polyethylene (PE) and ethylene vinyl acetate (EVA) (copolymer) in a weight ratio of 1 to 5: 1, preferably 2 to 3: 1. Could have been When the weight ratio between the two is out of the above range (if removed), the mechanical property improving effect (yes) can be weaker (smaller) than when the same kind of resin is used.

  Meanwhile, the step (a) may be performed at a temperature of 180 to 300 ° C, preferably 220 to 240 ° C, more preferably 230 ° C. If the process temperature in the step (a) is less than 180 ° C., the olefin polymer resin is partially melted to reduce the compression (extrusion) moldability and the dispersibility of the carbon nanotubes, exceeding 300 ° C. For example, thermal decomposition or modification of the olefin polymer resin may occur.

  In the step (a), the carbon nanotubes and the first olefin polymer resin can be compressed (extruded) at a rate of 10 to 500 kg / hr, preferably 10 to 30 kg / hr. If the compression (extruding) speed is less than 10 kg / hr, the productivity is lowered, and if it exceeds 500 kg / hr, the mixing uniformity of the carbon nanotube and the first olefin polymer resin can be lowered.

  The masterbatch that is the product of step (a) may include a high content of carbon nanotubes. For example, the content of the carbon nanotubes included in the master batch may be 10 to 30% by weight.

  If the content of the carbon nanotubes contained in the master batch is less than 10% by weight, the degree to which the carbon nanotubes are concentrated in the master batch is insignificant, and if it exceeds 30% by weight, the composition of the manufactured master batch May become non-uniform and workability may be reduced.

  The carbon nanotubes used in the production of the masterbatch are powdered ones that are mechanically and physically compressed into pellets, and the apparent density of the processed carbon nanotubes is 0.01-0. .2 g / ml, preferably 0.05-0.2 g / ml. When the apparent density of the carbon nanotubes is out of the above range (if removed), it is difficult to produce a concentrated master batch containing 10% by weight or more of carbon nanotubes. In addition, the carbon nanotubes processed into a pellet form can prevent the powder from being scattered during the work and improve the work environment.

  On the other hand, in the step (a), the compression (extruding) machine used at the time of compression (extruding) is a shortened compression (extruding) machine equipped with one screw, or multiaxial compression equipped with a plurality of screws. A (compression) machine, preferably a biaxial compression (compression) machine provided with two screws for uniform mixing and compression (compression) between components.

  At this time, in order to suppress the breakage of the carbon nanotubes in the kneading process using the compression (extruding) machine, the olefin polymer resin is preferably compressed (compressed) using a biaxial compression (extruding) machine. A method of melting and kneading can be used by charging from the machine side and supplying the carbon nanotubes to the compression (pressing) machine using a side feeder.

  In the step (b), the high content of carbon nanotubes contained in the master batch may be mixed with the second olefin polymer resin and diluted (let-down). The amount of the second olefin polymer resin administered in the step (b) may be such that the carbon nanotube content in the product conductive resin composition can be diluted to 0.1 to 10% by weight. It is enough.

  The second olefin polymer resin may be the same as the first olefin polymer resin or may be different from the first olefin polymer resin as necessary. However, in the case where the types of the first and second olefin polymer resins are different, one or more monomers contained in each of them are the same in consideration of the compatibility between them, Alternatively, those in which one or more resins contained in each of them are the same can be used.

  For example, when the first olefin polymer resin is a mixture of polyethylene and ethylene vinyl acetate (copolymer), the second olefin polymer resin is polyethylene, a polyethylene copolymer, or a mixture thereof. obtain.

  The conductive resin composition manufactured through the steps (a) and (b) is manufactured without using a conventional manufacturing method, for example, a master batch, while using a high-viscosity olefin polymer resin as a base material. Compared with the conductive resin composition, the electrical conductivity can be improved, and at the same time, the mechanical properties can be maintained and both can be realized in a balanced manner.

  Specifically, the master batch and the second olefin polymer resin may be mixed and diluted such that the content of carbon nanotubes contained in the conductive resin composition is 0.1 to 10% by weight.

  If the content of the carbon nanotubes contained in the conductive resin composition is less than 0.1% by weight, the electrical conductivity may be reduced, and if it exceeds 10% by weight, the mechanical properties may be significantly reduced.

  In the step (b), the masterbatch and the second olefin polymer resin may be mixed by a melt mixing method, an in-situ polymerization method, a solution mixing method, or the like. Although it can be used, it is preferable to use a compression (extruding) machine, etc., and melt mixing that can increase the capacity and reduce manufacturing costs by uniformly dispersing carbon nanotubes in the resin under high temperature and high shear force The method can be used. The type, characteristics, selection criteria, etc. of the compressor (extruder) are as described above.

  In the step (a) or (b), a flame retardant, an impact reinforcing agent, a flame retardant auxiliary agent, a lubricant, a plasticizer, a heat stabilizer, an antistatic (loading) agent, depending on the purpose of use of the conductive resin composition, One or more additives selected from the group consisting of an antioxidant, a compatibilizer, a light stabilizer, a pigment, a dye, an inorganic additive, and an anti-drip agent may be additionally added.

  The content of the additive may be 0.1 to 10% by weight based on the total weight of the conductive resin composition. If the content of the additive is less than 0.1% by weight, it is difficult to realize an effect suitable for the intended purpose, and if it exceeds 10% by weight, the physical properties inherent to the olefin polymer resin can be lowered.

  The conductive resin composition is manufactured into a plastic molded product through injection, compression (extruding) molding, and the like, and uses a polyethylene resin, which can be applied in a wide range, as a base material. It can be used for electronic products, vehicle parts, and the like.

  In particular, the conductive resin composition is a vehicle component, specifically, a fuel tank, which requires a balanced and essential mechanical property of a certain level or more and electrical conductivity of a certain level or more. ) Or a vehicle fuel hose. Since the chemical, electrochemical and mechanical properties required for such a molded product can be completed through the steps (a) and (b), the conductive resin composition is molded by a mold. To get the final product.

In addition, a plastic molded product manufactured using the conductive resin composition is manufactured in a range in which the surface resistance is 10 ² to 10 ¹⁰ Ω / sq by adjusting the content of the carbon nanotube according to the application field. In particular, it can be produced in a range of 10 ² to 10 ⁸ Ω / sq in the field where antistatic properties and imparting excellent electrical conductivity are required.

Example 1
Multi-wall carbon nanotubes (MWCNT) are put into a side feeder (Side Feeder) of a twin screw compressor (extruder), and polyethylene (HDPE, melt index 5.0 g / 10 min, ASTM D 1238) is used as a main hopper (Main Hopper). Was added at a charging speed of 25 kg / hr, and then melt-kneaded at a kneading speed of 200 rpm and a processing temperature of 230 ° C. to produce a master batch having a carbon nanotube content of 10% by weight.

  The manufactured masterbatch and a different kind of polyethylene (HDPE, melt index 0.3 g / 10 min, ASTM D 1238) are put into a twin screw compression (extruding) machine and melt kneaded at a kneading speed of 200 rpm and a processing temperature of 250 ° C. Thus, a resin composition having a carbon nanotube content of 6% by weight was produced.

Example 2
The resin was prepared in the same manner as in Example 1 except that the content of carbon nanotubes contained in the master batch was adjusted to 10% by weight and the content of carbon nanotubes contained in the resin composition was 5% by weight. A composition was prepared.

Example 3
The resin was prepared in the same manner as in Example 1 except that the content of carbon nanotubes contained in the master batch was adjusted to 10% by weight and the content of carbon nanotubes contained in the resin composition was 4% by weight. A composition was prepared.

Example 4
The resin was prepared in the same manner as in Example 1 except that the content of carbon nanotubes contained in the master batch was adjusted to 10% by weight and the content of carbon nanotubes contained in the resin composition was adjusted to 3% by weight. A composition was prepared.

Example 5
Multi-wall carbon nanotubes (MWCNT) are charged into a side feeder (Side Feeder) of a twin screw compressor (extruder), polyethylene (HDPE, melt index 5.0 g / 10 min, ASTM D 1238) and ethylene vinyl acetate (EVA) (Copolymer) and a resin mixed at a weight ratio of 7: 3 are charged into a main hopper at a charging speed of 25 kg / hr, and then melt-kneaded at a mixing speed of 200 rpm and a processing temperature of 230 ° C. A master batch having a carbon nanotube content of 10% by weight was produced.

  Thereafter, a resin composition having a carbon nanotube content of 6% by weight was produced in the same manner as in Example 1.

Example 6
The resin was prepared in the same manner as in Example 5 except that the content of carbon nanotubes contained in the master batch was adjusted to 10% by weight and the content of carbon nanotubes contained in the resin composition was 5% by weight. A composition was prepared.

Example 7
The resin was prepared in the same manner as in Example 5 except that the content of carbon nanotubes contained in the master batch was adjusted to 10% by weight and the content of carbon nanotubes contained in the resin composition was 4% by weight. A composition was prepared.

Example 8
The resin was prepared in the same manner as in Example 5 except that the content of carbon nanotubes contained in the master batch was adjusted to 10% by weight and the content of carbon nanotubes contained in the resin composition was adjusted to 3% by weight. A composition was prepared.

Comparative Example 1
Multi-wall carbon nanotubes (MWCNT) are put into a side feeder (Side Feeder) of a twin screw compression (extruding) machine, and polyethylene (HDPE, melt index 0.3 g / 10 min, ASTM D 1238) is twin screw compression (extruding) ) After being charged into the machine at a charging speed of 25 kg / hr, melt-kneading was performed at a kneading speed of 200 rpm and a processing temperature of 250 ° C. to produce a resin composition having a carbon nanotube content of 6% by weight.

Comparative Example 2
A resin composition was produced in the same manner as in Comparative Example 1 except that the content of carbon nanotubes contained in the resin composition was adjusted to 5% by weight.

Comparative Example 3
A resin composition was produced in the same manner as in Comparative Example 1 except that the content of carbon nanotubes contained in the resin composition was adjusted to 4% by weight.

Comparative Example 4
A resin composition was produced in the same manner as in Comparative Example 1 except that the content of carbon nanotubes contained in the resin composition was adjusted to 3% by weight.

Experimental Example 1: Measurement of electrical conductivity according to production method and carbon nanotube content The resin compositions according to Examples 1 to 8 and Comparative Examples 1 to 4 were injected at 210 ° C. using a hydraulic injection machine, It was manufactured into an injection product having a rectangular shape having a size of 30 cm and a length of 20 cm.

  The surface resistance (Ω / sq) of each manufactured injection product was measured with a surface resistance measuring instrument (SIMCO, ST-4), and the result is shown in FIG.

Referring to FIG. 2, a carbon nanotube-polymer nanocomposite manufactured by diluting the carbon nanotube content after passing through the masterbatch manufacturing step is manufactured without passing through the masterbatch manufacturing step- Compared to the polymer nanocomposite, the surface resistance was the same (Examples 4 and 8 and Comparative Example 4) or decreased (Examples 1 to 3, Examples 5 to 7 and Comparative Examples 1 to 3). ^It was confirmed that the value was about ⁵ Ω / sq (Examples 1 and 5).

  In particular, in the section where the content of carbon nanotubes is increased from 4% by weight to 5% by weight, the carbon after the masterbatch manufacturing stage is compared with the case where the masterbatch manufacturing stage is not passed (Comparative Examples 2 and 3). When the nanotube content was diluted (Examples 2, 3, 6, and 7), a rapid decrease in surface resistance was observed, and it was confirmed that even a small change in the content of carbon nanotubes showed a further improved effect.

  In addition, in the production of the masterbatch, in the case where a mixture of polyethylene and ethylene vinyl acetate (copolymer) is used (Example 7), compared to the case where polyethylene is used alone as the thermoplastic resin (Example 3). It was confirmed that the conductive resin composition containing a certain amount of carbon nanotubes showed a further reduced surface resistance.

  Based on these results, even when carbon nanotubes, which are conductive fillers, are contained in the same content, it is possible to produce a masterbatch and dilute it at the time of manufacturing the conductive resin composition. Furthermore, it can be seen that the electrical conductivity can be further improved by using a mixture of different types of thermoplastic resins during the production of the masterbatch.

Comparative Example 5
Polyethylene containing no carbon nanotubes (HDPE, melt index 0.3 g / 10 min, ASTM D 1238) was used for the resin composition.

Experimental Example 2: Measurement of mechanical properties according to production method and carbon nanotube content The resin compositions according to Examples 1 to 8 and Comparative Examples 1 to 5 were injected at 250 ° C. using an injection machine to mechanically A specimen (sample) for measuring physical properties was manufactured. Each specimen (sample) was measured for Izod impact strength, tensile strength, and elongation by the following method, and the results are shown in FIGS.

  Izod impact strength (kgf · cm / cm): Measured according to ASTM D256 on a specimen having a thickness of 1/8 ″ (inch).

- tensile strength (kgf / cm ²⁾ and elongation (%): measured under the conditions of 20 mm / min based on ASTM D638.

  Referring to FIG. 3, the thermoplastic resin compositions (Examples 1 to 8 and Comparative Examples 1 to 4) prepared by adding carbon nanotubes compared to the thermoplastic resin to which carbon nanotubes are not added (Comparative Example 5). It can be seen that the impact strength is reduced.

  However, the resin compositions (Examples 1 to 8) produced by diluting the master batch after the production of the master batch were compared with the resin compositions (Comparative Examples 1 to 4) produced without the production of the master batch. It was confirmed that the reduction in impact strength was low.

  In particular, when the content of the carbon nanotube is 5% by weight, the resin composition (Example 6) manufactured so that the master batch contains a different kind of thermoplastic resin may contain a single thermoplastic resin. It was confirmed that the impact strength was about twice as high as that of the case (Example 2) produced in the above and the case where the master batch was not produced (Comparative Example 2).

  Referring to FIG. 4, the tensile strength of the resin composition increases as the amount of carbon nanotubes added increases compared to the thermoplastic resin to which carbon nanotubes as conductive fillers are not added (Comparative Example 5) (Example 1). To 8 and Comparative Examples 1 to 4), in particular, a resin composition (Examples 1 to 4) manufactured through a manufacturing stage of a masterbatch containing a single thermoplastic resin and a manufacturing stage of the masterbatch. It was confirmed that the tensile strengths of the resin compositions (Comparative Examples 1 to 4) produced without any change showed a similar increasing tendency as the carbon nanotube content increased.

  Referring to FIG. 5, the resin compositions (Examples 1 to 8) manufactured through the masterbatch manufacturing stage are inherent to the thermoplastic resin (Comparative Example 5) even if the content of carbon nanotubes increases. While maintaining the elongation, it was confirmed that the resin compositions (Comparative Examples 1 to 4) produced without passing through the masterbatch production stage showed a significant decrease in the elongation.

  Through these results, even if the conductive filler is included in the same content, there will be a slight difference in mechanical properties depending on the presence or absence of the masterbatch production stage. Specifically, the carbon nanotube content is diluted after the masterbatch production. It can be seen that the resin composition produced by the process exhibits more excellent mechanical properties.

  As described above, the embodiments of the present invention have been described with reference to the accompanying drawings. However, those who have ordinary knowledge in the technical field to which the present invention belongs may be used without departing from the technical idea of the present invention. Various substitutions, modifications, and changes are possible. Therefore, it should be understood that the above-described embodiments and examples are illustrative in all aspects and not limiting. For example, each component described as a single type can be implemented in a distributed manner, and components described as being similarly distributed can be implemented in a combined form.

  The scope of the present invention is indicated by the following claims, but all modifications or variations derived from the meaning and scope of the claims and equivalents thereof are included in the scope of the present invention. Must be interpreted.

Claims (12)

(A) compressing (pressing) the carbon nanotubes and the first olefin polymer resin to produce a master batch; and (b) mixing the master batch and the second olefin polymer resin. The manufacturing method of the conductive resin composition characterized by the above-mentioned.   The method for producing a conductive resin composition according to claim 1, wherein the step (a) is performed at a temperature of 180 to 300 ° C.   The method for producing a conductive resin composition according to claim 1 or 2, wherein in the step (a), the compression (extruding) is performed at a speed of 10 to 500 kg / hr.   The method for producing a conductive resin composition according to any one of claims 1 to 3, wherein the content of carbon nanotubes contained in the master batch is 10 to 30% by weight.   The method for producing a conductive resin composition according to claim 4, wherein the content of the carbon nanotubes contained in the conductive resin composition is 0.1 to 10% by weight.   The apparent density of the said carbon nanotube is 0.01-0.2 g / ml, The manufacturing method of the conductive resin composition of any one of Claims 1-5 characterized by the above-mentioned.   Each of the first and second olefin polymer resins is selected from the group consisting of high density polyethylene, low density polyethylene, linear low density polyethylene, polyethylene copolymer, polypropylene, and a mixture of two or more thereof. The method for producing a conductive resin composition according to any one of claims 1 to 6, wherein   The polyethylene copolymer is selected from the group consisting of ethylene vinyl acetate (copolymer), ethylene butyl acrylate (copolymer), ethylene ethyl acrylate (copolymer), and a mixture of two or more thereof. The method for producing a conductive resin composition according to claim 7, wherein   The conductive resin composition according to claim 7 or 8, wherein the first olefin polymer resin is a mixture of polyethylene and ethylene vinyl acetate (copolymer) in a weight ratio of 1 to 5: 1. Manufacturing method.   The conductive resin composition according to any one of claims 1 to 9, further comprising a step of pelletizing the product of the step (a) before the step (b). Method.   The method further comprises (c) a step of molding the conductive resin composition after the step (b) by the method for producing a conductive resin composition according to any one of claims 1 to 10. A method for manufacturing a fuel tank for a vehicle.   The method further comprises (c) a step of molding the conductive resin composition after the step (b) by the method for producing a conductive resin composition according to any one of claims 1 to 10. A method for manufacturing a vehicle fuel hose.