WO2019022528A1 - Polytetrafluoroethylene carbon nanotube composite having electro-conductive property and method for producing same - Google Patents

Abstract

The present invention relates to a polytetrafluoroethylene carbon nanotube composite and a method for producing same. The present invention can produce a polytetrafluoroethylene carbon nanotube composite having an electro-conductive property, the electrical resistance of which is indicated by volume resistivity of 1.0E+00Ω.㎝ to 1.0E-02Ω.㎝, the method comprising adding PTFE, CNT and an organic solvent and carrying out a primary agitation, producing an intermediate product by carrying out a second agitation after adding a metal coupling agent, centrifugally separating and removing the organic solvent from the intermediate product, and then drying and pulverizing to obtain a product. The polytetrafluoroethylene carbon nanotube composite can be produced as polymer resin material which can be an alternative to metal due to low electrical resistance while retaining PTFE properties.

Description

Polytetrafluoroethylene-Carbon Nanotube Composite Material Having Electrical Conductivity Function and Manufacturing Method Thereof

The present invention relates to a polytetrafluoroethylene-carbon nanotube composite material having an electrically conductive function capable of replacing metal by incorporating a carbon-based material into polytetrafluoroethylene (PTFE) resin having excellent chemical resistance and a method for producing the same .

There are a large number of industries that deal with hazardous chemicals in the industrial field. Hazardous compounds are strong acids, strong alkalis, toxic substances such as hydrochloric acid, nitric acid, and sulfuric acid, and there are chemical manufacturing plant PCBs and plating plants that make semiconductor harmful compounds.

However, in recent years, there has been an increase in the leakage of harmful compounds, resulting in an increase in property losses due to environmental accidents, secondary accidents caused by the fires, and accidents. Analysis of this accident shows that the carelessness of the workers is the biggest and the following is the lack of facility management. The key to such facility management is the need for a highly sensitive sensor with excellent chemical resistance to detect fluid leaks.

For example, in the semiconductor industry, a device for detecting a solution leakage in a process of washing with an acidic solution, that is, a high sensitivity sensor, is required, and excellent electrical conductivity is required for fast signal transmission. Metals, which are excellent electrical conductors, are unusable because of their very low chemical resistance to acidic materials.

In this way, there is no material for the sensor that can not use the metal because of the corrosion of the material of the sensor, and particles must not be generated in the high clean management area such as the semiconductor.

Therefore, a new material suitable for the sensor needs to be solved. The new material should not generate particles, and must have a chemical resistance that is not corroded, and can withstand high temperatures, especially metals that function as high- New materials are needed.

Conventionally, as a material which can replace metals, composite materials in which a conductive filler for electric conductivity is mixed with a polymer resin have been developed and used in various fields. A fine metallic powder such as known carbon black, graphite, silver, copper, nickel, aluminum and the like can be uniformly dispersed as a conductive filler in the production of a polymer resin There is a method of dispersion.

However, in order for these conductive fillers to impart conductivity to the polymer, it is necessary to form a pathway in which the fillers have continuity between the particles in the polymer resin. That is, the metal particles or the carbon black particles are in close contact with each other in the material, so that the conductive particles can jumping electrons to each other

For example, when carbon black is blended with a urethane resin to impart electrical conductivity, about 15 to 30% by weight of carbon black is used relative to the weight of the resin. However, in order to obtain better conductivity, the carbon black is used in an amount of 40% It is required to be used.

However, the introduction of such a large amount of carbon black makes it difficult for the particles to be uniformly dispersed, reduces the melt viscoelasticity of the resin, and causes the filler particles to aggregate with each other, resulting in an extremely increased viscosity. As a result, the self-characteristics of the polymer resin is remarkably lowered, and problems such as contamination due to abrasion and short-circuiting of electric conductivity occur. On the other hand, in the case of using a metal powder, the metal powder has a specific surface area smaller than that of carbon black and must be compounded by an amount of 2 to 3 times or more to cause conductivity. In this case, the dispersibility becomes poor and the specific gravity becomes heavy.

Specific examples that disclose a method for imparting conductivity to a polymer resin or an elastomer include those disclosed in Japanese Patent Laid-Open Nos. 9-000816, 2000-077891, 6,768,524, 6,784,363, and 4,548,862 have.

Examples of conductive composite materials using polymer resins and carbon nanotubes are disclosed in Korean Patent Laid-Open Publication No. 10-2012-0077647, " Method for producing a composite material of polymer / carbon nanotubes ", Korean Patent Laid-Open Publication No. 10-2011-0078154 &Quot; Carbon nanotube-polymer nanocomposite material using fluidized bed multiwall carbon nanotubes, and a manufacturing method thereof ".

However, the above-described prior art techniques require a high enough chemical resistance, such as a sensor material for detecting leakage of harmful chemical substances, as well as a sufficient electrical conductivity enough to replace a metal, It was not suitable as a material for a high-sensitivity sensor for solution leakage in the process.

Therefore, it is required to develop new materials that can be used in specific places and environments where it is required to prevent contamination such as chemical resistance, chemical resistance, chemical resistance, low electric resistance, and clean process.

SUMMARY OF THE INVENTION An object of the present invention is to provide a polytetrafluoroethylene (PTFE) resin having electrical conductivity which can be used in a specific place and environment in which contamination prevention such as strong chemical resistance, low electric resistance, Polyolefin-carbon nanotube composite material and a method for producing the same.

Also, an object of the present invention is to provide an electrically conductive polytetra polyolefin-carbon nanotube composite material having an electric resistance of 1.00E + 00? 占 ~ m to 1.00E-02? 占 체 m and a volume resistivity, and a process for producing the same .

The technical objects to be achieved by the present invention are not limited to the technical matters mentioned above, and other technical subjects which are not mentioned can be clearly understood by those skilled in the art from the following description.

SUMMARY OF THE INVENTION [0008]

PTFE (Polytetrafluoroethylene) resin, which is known to have the highest chemical resistance in the polymer material having excellent chemical resistance, was selected,

A multi-walled carbon nanotube (MWCNT), a state-of-the-art nano material known to have the highest electrical conductivity among the fillers to be filled in the polymer material for electrical conductivity,

The present invention can be achieved by providing a composite material in which MWCNT is synthesized as an electrically conductive filler in PTFE having chemical resistance and physical properties and a method for producing the composite material.

The present invention also provides a polytetrafluoroethylene-carbon nanotube composite material, wherein the polytetrafluoroethylene-carbon nanotube composite material has a volume resistivity of 1.0 E + 00 O. cm to 1.0 E-02 O. O. cm, And has electrical conductivity.

In order to accomplish the object of the present invention, there is provided a method for producing an electrically conductive polytetra polyolefin-multi-walled carbon nanotube composite material,

Preparing PFTE and MWCNT to prepare a nanoparticle by removing the aggregation phenomenon by Van der Waals force's and adjusting the temperature of the stirring chamber to a temperature within a preset range;

A feedstock feeding step of feeding PTFE powder, dispersed multi-wall carbon nanotubes, and organic solvent into the stirring chamber at a ratio of each raw material to a predetermined total amount;

A primary stirring step in which the pressure in the stirring chamber is controlled to a pressure within a predetermined range while stirring for a stirring time proportional to the total amount of raw material introduced;

A metal coupling agent injecting step of injecting a metal coupling agent in a predetermined amount proportional to the total raw material amount after the first stirring,

A second agitation step in which a metal coupling agent is added and then stirred for a predetermined time;

An organic solvent removing step of removing the liquid organic solvent after the second stirring;

And a low-temperature drying step of preparing a composite material in which a multi-walled carbon nanotube is synthesized on PTFE by low-temperature drying the composition from which a liquid organic solvent has been removed.

Further, according to the present invention,

The method further includes a step of comminuting the composite material to produce a powder, a sheet, a film, or a bar.

Further, in the first and second agitation steps according to the present invention,

A mixing screw rotating step of rotating the mixing screw inserted in the stirring chamber,

And a stirring chamber rotating step for rotating the stirring chamber in a direction opposite to the mixing screw.

Further, according to the present invention,

The mixing screw is rotated at a high rotation speed of 5,000 to 1,500 RPM, and the stirring chamber is rotated at a low speed of 1 to 200 RPM.

In addition,

The stirring chamber rotating step is characterized by repeatedly controlling on / off by an intermittent rotation method.

In addition, the raw material to be supplied by the present invention,

As compared with 100% by weight of the input raw materials,

10 to 30% by weight of PTFE powder, 1 to 10% by weight of MWCNT, 59.9 to 88.1% by weight of an organic solvent, and 0.1 to 0.9% by weight of a metal coupling agent.

Further, in the primary stirring step,

The stirring time at which the viscosity of the raw material to be stirred becomes 3,000 to 5,000 CPS is experimentally determined to determine the primary stirring time.

Also, the temperature of the stirring chamber is maintained at a temperature range of 30 to 60 degrees and the pressure is maintained at 10 to 20 N / cm < 2 >.

Further, in the step of removing the organic solvent,

And separating and removing the liquid organic solvent by using a centrifugal separator.

In order to implement the PTFE-CNT composite material manufacturing method as described above, an agitating chamber capable of heating and pressure control is used, and the agitating chamber includes an internal rotating screw and a double And the rotating screw and the stirring chamber rotate in opposite directions to multiply the rotational speed at which the materials charged into the chamber are mixed. By mixing the coupling agent at an appropriate viscosity with stirring at a high speed in the state where the appropriate heat and pressure are being applied and stirring it, grafting can be performed with a structure in which the CNTs are exchanged instead of one F in the PTFE molecular structure will be.

Therefore, conductive PTFE-CNT resin having low electric resistance which can substitute for metal can be manufactured, and it can be manufactured as a superconducting composite material while maintaining the characteristics of PTFE. Therefore, it is possible to manufacture a semiconductor process, a chemical manufacturing process, a PCB manufacturing process, A polytetrafluoroethylene-carbon nanotube composite material having an electrically conductive function of the present invention can be used as a material of a sensor for detecting leakage of harmful compounds having strong alkaline toxicity in the process.

In the present invention, PTFE (Polytetrafluoroethylene) resin, which is known to have the highest chemical resistance among polymer materials, is selected and PTFE + CNT composite material having electric conductivity function synthesized by adding CNT as a conductive filler is provided.

Accordingly, it is possible to provide a composite material having a superconducting function while maintaining the characteristics of the PTFE itself. Therefore, it is possible to provide a conductive material that can be used in specific places and environments where it is required to prevent contamination such as chemical resistance, It is possible to provide a polymer composite material.

In addition, although the present invention has not been able to achieve a low electrical resistance (volume resistivity of 1.0E + 00Ω.cm to 1.0E-02Ω.cm) to date, the composition of the present invention (1.0E + 00Ω.cm to 1.0E-02Ω. Cm. ≪ / RTI > Volume Resistivity).

The present invention can be applied to various fields such as electric, electronic, communication, automobile, medical, aviation, etc. using the superconducting PTFE + CNT nanocomposite material according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a classification comparison chart of electrical resistance of a composition to which electrical conductivity is imparted to a polymer resin. FIG.

2 is a manufacturing process diagram for explaining an embodiment of the present invention.

3 is a graph of change in electrical resistance according to the amount of carbon nanotubes according to the present invention.

Figs. 4A to 4C are comparative photographs showing measurement of gloss and contamination on the surface of a conductive PTFE composite material,

4A is a photograph of a conventional conductive PTFE material,

4B is a photograph of a CNT 5% + PTFE composite material,

4C is a photograph of a CNT 5% + PTFE + coupling agent (C) composite material according to the present invention.

5A to 5C are explanatory diagrams for measuring the electric volume resistance of the PTFE + MWCNT composite material according to the present invention,

Figure 5A illustrates the measurement of a specimen within one inch spacing,

Fig. 5B shows a volume resistance measuring instrument,

5C is an explanatory view for measuring the electric volume resistance by combining a plug electrode and a minus electrode pin at a distance of less than 1 inch to the specimen

Hereinafter, with reference to the accompanying drawings, a method of manufacturing a composite material of PTFE + CNT and a resistance value of a superconducting polymer resin to replace a metal will be described with reference to the accompanying drawings. The application and modification contents not described here are sufficiently technically inferior to those skilled in the art, so that the description thereof will be omitted.

The present invention provides a polytetrafluoroethylene-carbon nanotube composite material having an electrically conductive function in which carbon nanotubes are bonded to polytetrafluoroethylene (PTFE) for imparting electrical conductivity.

The polytetrafluoroethylene (PTFE) is a material excellent in chemical resistance, non-tackiness, antifouling property, heat resistance and friction characteristics, and carbon nanotubes are used to impart electric conductivity which is insufficient in PTFE, so that the whole composite material has electric conductivity do.

Accordingly, the present invention can provide a composite material having excellent electrical conductivity such as a metal while maintaining the basic properties of polytetrafluoroethylene.

The present invention was developed based on polytetrafluoroethylene (PTFE) (CF ₂ CF ₂ ), which is superior in chemical stability among polymer materials.

Polytetrafluoroethylene (PTFE) is excellent in various properties such as chemical resistance, electrical characteristic, non-tackiness, antifouling property, heat resistance and friction characteristics. PTFE materials are commonly used in various applications such as sealing of rotors, friction and gaskets, o-rings, chemical transfer pipes, heat-resistant anti-fouling films, It is widely used in industry.

Since PTFE (Polytetra fluoroethylene) does not accept other external substances, the chemical and antifouling properties are the best among the existing polymer materials. However, due to such excellent properties, it is very difficult to impart electrical conductivity to PTFE (Polytetra fluoroethylene) polymer resin with a special function.

On the other hand, to replace the metal, the electrical resistance should show a minimum resistance (<1.0E + 00Ω.cm Volume Resistivity).

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a classification comparison chart of electrical resistance of a composition to which electrical conductivity is imparted to a polymer resin. Fig.

A general polymer resin has a volume resistivity (<1.00E + 13Ω.cm to 1.00E + 14Ω.cm ↑) as an insulator, and a conductive filler is added to the polymer resin Dissipative of electric resistance (1.00E + 07Ω.cm to 1.00E + 12Ω.cm), antisatic of electric resistance (1.00E + 04Ω.cm to 1.00E + 06Ω.cm) (1.00E + 01.OMEG.CM to 1.00E + 3 .OMEGA.cm), and the conventional compositions containing the conductive filler in the polymer resin are applicable. The electric resistance of general PTFE resin shows (1.0E + 15Ω.cm).

The electrical resistance required to replace the metal is less than 1.00E + 00 ?. OMEGA. Cm. However, it has not been possible to achieve a low electrical resistance (volume resistivity of 1.0E + 00 ?. to 1.0E-02? The PTFE + MWCNT composites achieved electrical resistance of (1.00E-01Ω.cm to 1.00E-02Ω.cm volume resistivity).

(1.0E + 00.OMEGA.cm to 1.0E-02. ohm): 1.0 is an integer, indicating that + is not a positive number, and 00 to a negative power of 10 and a minus 2 power of -0210.

In order to impart electric conductivity to a polymer material of PTFE (Polytetrafluoroethylene) by applying a method for imparting electrical conductivity to a general polymer resin, one or more of carbon-based carbon black, carbon nanotubes, graphene, But it is very difficult to synthesize, and there is no domestic material producer.

In terms of competition, there is no composite material that synthesizes PTFE and CNT globally, so it can not be directly compared, but the company that is the most advanced in this field can be regarded as Saint Gobain of France. St. Govain uses carbon black as a conductive material, which is problematic for use in high-clean areas due to particles. The specification of conductive PTFE product of Goba is very different from -2 ohm which can be used as a substitute metal as 3 ohms in electric resistance. Another company is Dyneon Corp, which has a durability and application limitations because the material is in the form of ink using Carbon Black (INK).

In addition, graphene, carbon black, graphite, carbon fibers and the like are inferior to carbon nanotubes in terms of electrical conductivity. In order to jumping electrons to each other, conductive particles must be added in a large amount, , Abrasion, and contamination. In the electrically conductive region, a mixture of carbon nanotubes and one or more materials has a good effect, but a contamination due to a short circuit occurs when mixed.

Further, the above-mentioned PTFE product of Goba can not have electrical conductivity enough to replace the metal (< 1.0E + 03 ?. cm. Volume resistivity) and is difficult to use in places such as a sensor field requiring sensitivity. There are many limitations in the field of use.

Accordingly, the present invention solves the problem of contamination by abrasion or the like, and it is solved by solely injecting the carbon nanotubes as a conductive filler, and the problem of the electric conductivity is solved by using a carbon nanotube and PTFE in a graft method To combine with PTFE on a matrix to maximize the electrical conductivity of carbon nanotubes and solve the problem of short circuit contamination. Here, the carbon nanotubes may be single wall carbon nanotubes or multi wall carbon nanotubes, but multiwall carbon nanotubes are used in the aspect ratio.

In the present invention, PTFE, MWCNT, and an organic solvent are placed in a stirring chamber and stirred. Then, a metal coupling agent is added thereto and stirred, and then the organic solvent is removed using a centrifuge to prepare a composition. A multi-walled carbon nanotube (PTFE) is added to the polymer substance PTFE (Polytetra fluoroethylene) so as to have electrical conductivity such as resistance (<1.0E + 00Ω.cm to 1.0E-2Ω.cm volume resistivity) It is possible to provide a PTFE + MWCNT composite material having an electric conductivity function that maintains the properties such as chemical resistance, abrasion resistance, high heat resistance, and high gloss of PTFE while maintaining sufficient electrical conductivity to replace the metal.

[Example 1]

2 is a manufacturing process diagram for explaining an embodiment of the present invention.

The order of PTFE + MWCNT composites composition was 100 weight%

1. Preparation step (S10) of automatically cooling and heating the stirring chamber temperature by 30 to 60 degrees.

2. Add 10 wt% to 30 wt% of a PTFE powder (10um to 250um) resin into a stirring chamber, add 1 wt% to 10 wt% of MWCNT carbon nanotubes to a stirring chamber, add organic solvent VOC (Volatile Organic Compounds) 59.9 wt.% To 88.1 wt.%.

3. A primary agitation step (S30) in which the agitator mixing screw is driven to change the RPM of 5,000 to 15,000 while adjusting the agitator pressure (10 to 20 N / cm2) .

4. When the viscosity of the inside of the stirring chamber is 3,000 CPS to 5,000 CPS, a metal coupling agent is injected at a rate of 0.1% by weight to 0.9% by weight of the metal coupling agent (S40).

5. Second stirring step (S50) in which the reaction is stopped by stirring the reaction for 30 minutes to 60 minutes after the metal coupling agent is added.

6. Transferring from the stirring chamber to the centrifugal separator to remove the organic solvent in the liquid phase (S60).

7. A low-temperature drying step (S70) in which the remaining gas (< 50 PPM) of the composite material composition in which the liquid organic solvent is removed is managed.

8. The composite material completed in the low-temperature drying step (S70) may be pulverized into a suitable size for commercialization and then commercialized as a powder, or may be formed into a sheet or a bar using powders.

In the manufacturing method according to the present invention,

In preparation step S10, PTFE powder, MWCNT powder, organic solvent and metal coupling agent are prepared as raw materials. Here, the MWCNT may use single-walled carbon nanotubes, and preferably multi-walled carbon nanotubes. In addition, carbon nanotubes use a dispersed MWCNT as a material having its own aggregation phenomenon. That is, a van der Waals force is weakened to prepare a dispersed MWCNT in which the aggregation due to the ambient temperature is removed. The stirring chamber is adjusted to a suitable temperature. In the experiment of the present invention, the temperature is adjusted to 30 to 60 ° C.

In the raw material input step S20, PTFE powder, MWCNT powder, and organic solvent are introduced. The organic solvent is solvent, and PTFE is put into a size of 10-50 nm. When the organic solvent containing solvent is added and stirred, the PTFE's van der Waals force is weakened Thereby preventing re-aggregation. The CNTs are loaded with 5 to 15 nm of dispersed multiwall carbon nanotubes (MWCNT).

In the primary stirring step (S30), the rotating screw inserted in the stirring chamber and the stirring chamber itself are rotated and stirred. At this time, the temperature and pressure inside the stirring chamber should be appropriately adjusted.

The temperature starts stirring at about 10 ° C or higher as set in the preparation step, and the pressure starts stirring at a pressure of about 1 atm, that is, 10 N / cm 2. That is, in the initial start step, stirring can be started at normal room temperature and atmospheric pressure without separately adjusting pressure and temperature.

However, during the stirring, the temperature rise and the pressure increase, so it is necessary to adjust to keep the temperature and pressure range obtained experimentally.

Preferably, the temperature is increased to 10 to 30 DEG C at the start of stirring, but not more than 100 DEG C in the stirring step, stirring is started at a pressure of 10 N / cm2 at the start step, / Cm &lt; 2 &gt;.

In the stirring method, the rotating screw in the stirring chamber is rotated while varying the speed in the range of 5,000 to 15,000 RPM, and the stirring chamber is rotated while varying the speed in the range of 10 to 200 RPM.

At this time, the rotating screw in the stirrer and the stirring chamber are rotated in opposite directions to perform double reverse rotation, so that the rotational pressure to be received by the materials to be agitated is doubled, so that stirring is further performed.

The internal pressure and the temperature are raised by high-speed rotation stirring. The pressure is limited to about 10 N / cm 2 to 20 N / cm 2, and the temperature should not exceed 100 ° C. The temperature and the pressure may be controlled by providing a temperature control means and a pressure control means in the stirring chamber and controlling the stirring speed to be interlocked.

In the step of injecting the metal coupling agent (S40), when the viscosity of the stirring material is a predetermined viscosity, the metal coupling agent is charged with the capacity according to the predetermined recipe. It is difficult to measure the viscosity of the substance to be stirred in the stirring chamber.

Therefore, the primary stirring time is determined experimentally to determine the viscosity of the raw material to be 3,000 CPS to 5,000 CPS in accordance with the total amount of raw material input, and the primary stirring time is determined.

Accordingly, when the primary stirring time corresponding to the total amount of the starting material is elapsed, the viscosity of the stirring internal material is expected to be in the range of 3,000 to 5,000 CPS, and when the primary stirring time has elapsed, the metal coupling agent is introduced .

The metal-coupling agent is a metal-oxide-based (C 60 H 123 O 15 P 3 Ti) nanocoupling agent to increase the affinity and the reaction between PTFE and one or more substances and the interface, To 0.3% by weight to 0.6% by weight.

The second agitation step (S50) is a step of injecting a metal coupling agent and performing reaction stirring, and the temperature, pressure, and time are experimentally determined and a secondary stirring step is performed according to the determined recipe. When the secondary agitation is carried out, the solid absorbs the gas and the liquid to form an 80 wt% paste-state intermediate product.

In the organic solvent removing step (S60), the paste-like intermediate product produced by the stirring step is transferred to a centrifuge to separate liquid and gas.

In the low-temperature drying step (S70), the organic solvent in the liquid state is removed from the intermediate product, and the intermediate product in the paste state is dried at low temperature together with the dehumidification. If desired, the desired composition can be obtained by making it bake by low temperature drying.

Thereafter, the thus obtained composition is made into a product according to the intended use. Powdered powder obtained by crushing the baked composition into a pulverized composition or a sheet or rod obtained by crushing the powder into a sheet or rod is extruded or otherwise produced into a desired shape.

The present invention provides a PTFE + CNT composite material having an electrically conductive function manufactured by the above-described production method.

The optimal ratio, optimal pressure, and optimal temperature conditions for PTFE + CNT agitation,

(C60H123O15P3Ti) Nano Coupling Agent Weight was added in an amount of 0.3% by weight to 0.6% by weight in 100% by weight of the weight of the PTFE and one or more materials to improve the affinity and reactivity between the interface and the interface. The chamber temperature was maintained at 60 to 70 ° C in the second stirring step, the graft method was performed under the conditions of a pressure of 10 to 20 N / cm 2, a mixing screw rotating speed of 5,000 to 10,000 RPM and a time of 30 to 60 minutes. , And the mechanical properties and electrical properties of PTFE were compared with each other [Table 1]. At this time, the best results were obtained in terms of mechanical properties, electrical properties and appearance.

The composite material obtained by synthesizing CNT with PFFE can be described as the following structural formula.

[constitutional formula]

(n is an integer)

The left side of the above [Structural Formula] is a basic structural formula of PTFE, and the right side is a structural formula for a composite material of the present invention having CNT bonded to PTFE. That is, in the unit structure of PTFE, one "F" is replaced with "CNT". The present invention is not a simple mixing of powders but a graft polymerization method.

Heat is applied to the bond between the PTFE molecules to increase the potential between the molecules. The optimum temperature is the ideal temperature of PTFE melting point (about 325 ℃), but unfortunately PTFE is hardened by heat and grafting process with carbon nanotubes is impossible.

Therefore, the high heat should be done in the final product molding operation. In this developed product, a pressure chamber is used to widen the distance between the molecules by using the minimum heat. The pressure is increased from 10 N / Lt; 2 &gt; Through the above-described experiment, it was confirmed that the composition of the present invention has better physical properties than those of conventional products.

In addition, the carbon nanotubes used in the present invention were prepared by dispersing MWCNTs having improved bundles, and the Aspect Ratio had an aspect ratio (diameter) of 5 nm or less and a length of 50 nm or less Respectively. In this study, the aspect ratio of the composition was the most excellent.

3 is a graph of electrical resistance change according to the amount of carbon nanotubes according to the present invention.

In order to obtain a low resistance value, the weight% of the carbon nanotubes in the composition weight 100% by weight is 3 to 4% by weight, the volume resistivity is 1.0E + The weight of 1.0E-02? Cm is preferably 4 to 6%, and in order to obtain a further lower resistance value, 7 to 10% by weight is added, but the electrical resistivity volume resistivity 1.0E-02? . The target value of the experiment was expected to decrease in proportion to increasing the CNT input amount, but it can be seen that there is a convergence section in which there is substantially no change in resistance.

3, when the CNT is not added to the PTFE, the electric resistance is 1.0E + 14 ?. cm, the electric resistance is 1.0E-01? 占 시 m when the CNT is 5wt%, the electric resistance is 6wt% The electric resistance of 1.0E-02 ?. cm was obtained and the electrical resistance at 1.0 wt% of CNT was 1.0E-02 ?. cm.

In this experiment, the carbon nanotubes showed a maximum range of 1.0E-02? 占 함 m of the composition weight 100% by weight of the sugar content of 6 wt% to 7 wt%, and the convergence interval in which the electrical resistance did not change was confirmed even when the addition amount was increased.

(C 60 H 123 O 15 P 3 Ti) nanocoupling agent at a weight of 100% by weight in an amount of 0.3% to 0.6% by weight in order to increase the affinity between the PTFE and one or more materials and the interface, (Grafted Polymer) was prepared by maintaining the chamber temperature at 60 ℃ ~ 70 ℃, pressure 10 ~ 20N / ㎠, mixing screw 5,000 ~ 10,000 RPM, time 30 ~ polytetrafluoroethylene) were compared with each other.

Comparison of mechanical properties and physical properties of conventional PTFE (polytetrafluoroethylene) and R & D PTFE

	Tensile strength kgf / cm 2 ASTM D638	Flexural elasticity kgf / ㎠ ASTM D790	Impact Strength kqf / ㎠ ASTM D256	Specific gravity ASTM D792	Exterior	Resistance Ω.cm ASTM D257
Existing product	250 to 350	4,650	10-12	2.0 to 2.2	Great	1.0E + 02 ~ 03
The present invention product	400 to 500	5,800	11-13	2.0 to 2.2	Very good	1.0E-01 to -02

Here, the existing product is a conductive PTFE product of St. Gobain, France, and the existing product was compared with the present invention product produced by the present invention. Compared with the conventional carbon black added product, the product according to the present invention is improved almost in the field of measurement, and it can be seen that it has a low electric resistance which is possible to substitute metal.

In the present invention, a sheet having a composition of 0.3 mm in thickness was prepared, specimens were produced by a conventional method, and tensile strength, flexural elasticity, impact strength and specific gravity were measured and compared, and appearance was visually judged. And the result is measured through a measuring device.

As a result of comparing the existing product with the present invention product, the tensile strength, flexural elasticity and impact strength were superior to those of the conventional products, the specific gravity was the same, and the appearance was excellent. Especially, And it is found that the resistance value for the purpose of replacing the metal is sufficiently realized.

4A is a photograph of a general conductive PTFE material, FIG. 4B is a photograph of a CNT 5% + PTFE composite material, FIG. 4C is a photograph of the present invention (CN) 5% + PTFE + coupling agent (CA) composite.

FIGS. 5A to 5C are explanatory views for measuring the electric volume resistance of the PTFE + MWCNT composite material according to the present invention, wherein FIG. 5A illustrates measurement of a specimen within an interval of 1 inch, FIG. 5B illustrates a volume resistance measurement device And FIG. 5C is an explanatory diagram of measuring the electric volume resistance by connecting the plug electrode and the negative electrode pin at a distance of less than 1 inch to the specimen.

The composition of the present study and the existing products and research and development products were made into a film of 0.3 mm, and the state of the surface and the degree of contamination were measured and verified.

The general conductive PTFE material of FIG.

Conductive PTFE containing carbon black of the existing foreign company was sampled, which caused sludge formation due to abrasion and electrical conductivity short circuit.

The CNT 5% + PTFE composite material of FIG. 4 (b)

The present invention relates to a composite material prepared by adding 5 wt% of CNT to PTFE, and the surface state of the composite material is poor due to the appearance of white specks and pinholes on the surface.

 The CNT 5% + PTFE + coupling agent (C.A) composite material according to the present invention in FIG.

5% by weight of carbon nanotubes and coupling agent were added to PTFE to give excellent results in surface roughness and dispersion contamination. That is, when 5 wt% of CNT was added to PTFE, a metal coupling agent (C.A.) was added and stirred to obtain the best result.

Comparative evaluation of composition (?: Very good,?: Good,?: Fair, X: poor)

	▶ Existing Conductive PTFE	▶ Carbon Nanotube 5% ▶ PTFE	▶ Carbon Nanotube 5% ▶ PTFE ▶ Coupling Agent	▶ Carbon Nanotube 8% ▶ PTFE ▶ Coupling Agent
Composition	○	X	◎	△
Cross section of composition	○	X	◎	△
Composition and Contamination	X	△	◎	△

Here, conventional conductive PFTE samples a conductive PTFE to which Goba's carbon block is added.

The appearance of the sample sheet was visually inspected for the appearance of each sample sheet, and the cross section of the inner surface was observed. The illuminance and the degree of contamination were the illuminance reflectance, and the degree of contamination was the degree of contamination Respectively.

In addition, although it is not shown in the table, the electric conductivity of the sheet was measured at each position of the whole area of the sheet using the measuring contact as shown in Fig. 5 (c).

The electric volume resistance of the PTFE + CNT composite material according to the present invention was measured by preparing a sheet having a thickness of 0.3 mm as shown in Fig. 5 (a), preparing a specimen having a width of 1 inch, i.e., 15 cm x 10 cm x 0.3 mm , And foreign substances on the surface are removed.

Thereafter, a volume resistance in a 1 inch / sq interval was measured according to the ASTM D257 measurement method using a low resistance meter (HIOKI M-3548) as shown in FIG. 5 (B). The resistance of the measurement band was maintained at 1.0E + 14Ω.cm or more.

The specimen prepared by the present invention, that is, the composite material prepared by stirring 5 wt% of CNT and coupling agent into PTFE was measured by the above measurement method, and as a result, the result of 1.0E-02? .

As described above, PTFE (Polytetrafluoroethylene) resin, which is known to have the highest chemical resistance among the polymer materials, was selected as described above. The electrical resistance of general PTFE resin shows the volume resistivity (1.0E + 15Ω.cm). The volume resistivity of 1.0E + 00Ω.cm to 1.0E-02Ω.cm, which is a low electric resistance range, has not been possible. However, the composition of the present invention has a volume resistance of 1.0E + 00Ω.cm to 1.0E-02Ω.cm )).

PTFE (Polytetrafluoroethylene) has already been widely used in the chemical industry. However, the electrical resistance of conventional conductive PTFE material (1.0E + 01Ω.cm to 1.0E + 03Ω.cm volume resistivity) It is developed by incorporating metal, which causes problems of wear and contamination.

Therefore, its use is extremely limited in certain places and environments where it is required to prevent contamination such as chemical resistance, chemical resistance, low electric resistance and clean process.

The present invention solves the above problems and maintains the PTFE (Polytetrafluoroethylene) own properties and realizes superior electrical resistance (1.0E + 00Ω.cm to 1.0E-02Ω.cm) than conventional products. It has proven to be very effective in pollution.

This result does not solve the problem of resistance and contamination simply because the content of the conductive material is increased. In order to overcome this problem, the present R & D composition has resulted in various experiments as shown in FIG. 3, FIG. 4 and [Table 1] and [Table 2].

We have succeeded in development of products with 10 times to 100,000 times better electrical resistance than existing conductive PTFE (Polytetrafluoroethylene) products and no pollution caused by carbon. This is the high price of conductive PTFE products that depend on national economic development and importation, , Has solved the A / S problem and can be widely used in various industrial fields such as semiconductor, chemical, medical, electromagnetic (EMC) design and so on.

As described in the present invention, the superconducting PTFE + CNT nanocomposite resin has been found to be superior to the conventional products, and it can be applied to various fields such as electric, electronic, communication, automobile, medical, Of the product.

Claims (13)

1. Polytetrafluoroethylene (PTFE); And

   Carbon nanotubes;

   Wherein the polytetrafluoroethylene-carbon nanotube composite material has an electrically conductive function.
2. The polytetrafluoroethylene-carbon nanotube composite material according to claim 1, wherein the polytetrafluoroethylene-

   A volume resistivity of 1.0E + 00? Cm to 1.0E-02? Cm;

   Wherein the polytetrafluoroethylene-carbon nanotube composite material has an electrically conductive function.
3. The method according to claim 1,

   A composite material of polytetrafluoroethylene-carbon nanotubes having an electrically conductive function, further comprising a metal coupling agent added to graft-couple CNT to PTFE.
4. The carbon nanotube according to claim 1,

   Single-walled carbon nanotubes or multi-walled carbon nanotubes

   Wherein the polytetrafluoroethylene-carbon nanotube composite material has an electrically conductive function.
5. A raw material charging step of charging PTFE powder, carbon nanotube, and organic solvent into the stirring chamber at a ratio of each raw material to a predetermined total amount;

   A first agitation step of agitating the agitating chamber for a stirring time proportional to the total amount of raw materials while adjusting the temperature and pressure of the agitating chamber within a predetermined range;

   A metal coupling agent injecting step of injecting a metal coupling agent in a predetermined amount proportional to the total raw material amount after the first stirring,

   A second agitation step in which a metal coupling agent is added and then stirred for a predetermined time;

   An organic solvent removing step of removing the liquid organic solvent after the second stirring;

   A low-temperature drying step of preparing a composite material in which a multi-walled carbon nanotube is synthesized in PTFE by low-temperature drying a composition in which a liquid organic solvent is removed;

   Wherein the polytetrafluoroethylene-carbon nanotube composite material is produced by performing the following steps.
6. 6. The method of claim 5,

   Characterized in that the product produced in the drying step is pulverized and processed into a powder, a sheet, a film or a bar product. The electroconductive polytetrafluoroethylene A method for producing an ethylene - carbon nanotube composite material.
7. [6] The method of claim 5,

   Wherein the multi-wall carbon nanotube is a dispersion-treated multi-wall carbon nanotube.
8. 6. The method of claim 5, wherein the primary and secondary agitation steps comprise:

   A mixing screw rotating step of rotating the mixing screw inserted in the stirring chamber,

   And rotating the stirring chamber in a direction opposite to the mixing screw. The method of claim 1, wherein the mixing chamber is rotated in a direction opposite to the mixing screw.
9. 9. The method of claim 8, wherein the primary and secondary agitation steps comprise:

   Wherein the mixing screw is rotated at a high rotation speed of 5,000 to 1,500 RPM and the stirring chamber is rotated at a low speed of 1 to 200 RPM to obtain a polytetrafluoroethylene-carbon nanotube composite material having electrical conductivity. Gt;
10. 9. The method of claim 8, wherein the primary and secondary agitation steps comprise:

    And stirring the mixture while varying the rotation speed of the mixing screw and the rotation speed of the stirring chamber. The method for producing a composite material of polytetrafluoroethylene-carbon nanotubes having electrical conductivity according to claim 1,
11. 9. The method according to claim 8, wherein the stirring chamber rotating step is repeatedly controlled to be turned on / off in an intermittent rotation manner.
12. 6. The method according to claim 5,

    A method for producing an electroconductive polytetrapolyolefin-carbon nanotube composite material, characterized in that a stirring time at which a viscosity of a raw material to be stirred is 3,000 to 5,000 CPS is experimentally determined to determine a primary stirring time .
13. 6. The method according to claim 5,

    As compared with 100% by weight of the input raw materials,

    Wherein the polytetrafluoroethylene is produced by charging 10 to 30% by weight of PTFE powder, 1 to 10% by weight of MWCNT, 59.9 to 88.1% by weight of an organic solvent, and 0.1 to 0.9% by weight of a metal coupling agent. Method for manufacturing carbon nanotube composite material.

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