KR20240033736A - PAEK-based conductive composite and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a PAEK-based conductive composite, comprising: a matrix comprising a first polymer and a second polymer having a higher viscosity than the first polymer; It relates to a PAEK-based conductive composite, characterized in that it has a uniform surface resistance of 10 ³ to 10 ⁹ Ω/sq, including carbon nanotubes dispersed in the matrix.

Description

PAEK-based conductive composite and manufacturing method thereof}

The present invention relates to a PAEK-based conductive composite, which is characterized in that the surface resistance of the composite is uniformed by more uniformly dispersing carbon nanotubes, which are conductive fillers, in the polymer, and to a method for manufacturing the same.

Polymers have excellent properties such as lightness, various moldability, and chemical resistance, as well as easy coloring and a beautiful appearance, so they are widely used in packaging materials, building materials, electrical device housings, household miscellaneous goods, and automobile interior parts. However, unlike metals, polymers are electrically insulating, so they have the property of accumulating static electricity generated by friction, etc. for a long time, and can cause various problems due to discharge, attraction, and repulsion due to charged static electricity. In order to prevent electrostatic disturbance of polymers, electrostatic dispersion or radiation that removes, neutralizes, and leaks generated charges is essential.

To this end, a conductive polymer composite is prepared by dispersing a conductive additive in a polymer matrix. Conductive polymer composites can be classified into electromagnetic shielding polymers, ESD (electrostatic dissipation) polymers, and antistatic polymers depending on the range of surface resistance. The conductive fillers include carbon black, carbon fiber, and carbon, which have high electrical conductivity. Nanotubes (CNT: Carbon Nanotube), etc. may be applied.

However, their use is limited due to slugging and dust generation, and they have problems such as low impact strength of the material and low formability, which limits market expansion.

Therefore, recently, as an alternative to the high-end market, MWCNT (Multi-Wall Carbon NanoTube), SWCNT (Single-Wall Carbon Nanotube), which are materials with high conductivity that can provide static dissipation performance with just a small amount of addition, have been used as alternatives to the high-end market. Technology is being developed for electrostatic dissipation polymers that use carbon nanotubes (CNTs) such as Carbon NanoTube (Single-Walled Carbon Nanotube) as conductive fillers.

For example, in Korean Patent Publication No. 10-1678724, bundle-shaped carbon nanotubes are added as a conductive filler to a thermoplastic resin and extruded or injected to manufacture an electrically conductive molded article. However, in the case of prior literature, this effect is achieved by changing the shape, diameter, and average length of the carbon nanotube itself, and I _D /I _G in Raman spectroscopy, so there may be technical and process difficulties in implementing this. Since commercially available carbon nanotubes cannot be used, it is somewhat less economical.

Additionally, Japanese Patent Publication No. 2010-540687 discloses manufacturing a conductive composite by producing a master batch based on carbon nanotubes and then introducing it into a thermoplastic and/or elastomeric polymer composition. In the case of prior literature, carbon nanotubes are first manufactured as a masterbatch and then introduced into a polymer to improve the dispersibility of carbon nanotubes.

However, as in prior literature, simply manufacturing carbon nanotubes as a master batch has limitations in uniformly dispersing carbon nanotubes throughout the polymer, making it difficult to equalize the surface resistance of the composite.

Therefore, there is a need for the development of a new conductive composite and its manufacturing method that can not only exhibit uniform surface resistance while adding a small amount of carbon nanotubes as a conductive filler, but also improve process efficiency and economic feasibility by simplifying the process. .

Korean Patent Publication No. 10-1678724 (registration date: 2016.11.16.) Japanese Patent Publication No. 2010-540687 (publication date: December 24, 2010)

The present invention seeks to provide a conductive composite that includes carbon nanotubes as a conductive filler like the prior art, but complements the dispersibility of the carbon nanotubes so that the composite has a more uniform surface resistance.

In addition, the present invention provides a method of manufacturing a conductive composite in which carbon nanotubes are uniformly dispersed in a polymer matrix, thereby uniformizing the surface resistance of the composite.

In order to solve the above problem, the present invention includes, in one aspect, a matrix including a first polymer and a second polymer having a higher viscosity than the first polymer; and carbon nanotubes dispersed in the matrix. It provides a PAEK-based conductive composite, characterized in that it has a uniform surface resistance of 10 ³ to 10 ⁹ Ω/sq.

In one embodiment, the coefficient of variation of the surface resistance may be 0.01 to 0.08.

In one embodiment, the difference in melt flow rate (MVR) between the first polymer and the second polymer may be 40 to 70 cm3/10 min at 380°C/5kg.

In one embodiment, the difference in melt viscosity between the first polymer and the second polymer may be 200 to 1000 Pa·s at 400° C. and a shear rate of 100/s.

In one embodiment, the first polymer and the second polymer may be in the same or different form selected from pellets and powders, and the first polymer and the second polymer may be 25 to 80:20. It can be mixed in a ratio of ~75 or 20~75:25~80.

In one embodiment, the carbon nanotubes may be included in an amount of more than 0.75% by weight and less than 5% by weight based on the total weight of the conductive composite.

In another aspect, the present invention includes the steps of melting and mixing a first polymer and carbon nanotubes in a first extruder to produce a masterbatch; and mixing the masterbatch with a second polymer having a higher or lower viscosity than the first polymer in a second extruder to produce a composite.

As an example, the masterbatch:second polymer may be mixed in a ratio of 30 to 80:20 to 70 based on weight percent.

The composite according to the present invention contains a small amount of carbon nanotubes and has uniform surface resistance by uniformly dispersing them on the polymer.

Therefore, the composite of the present invention can exhibit conductivity, electromagnetic shielding, ESD, and antistatic performance, and is used in semiconductor processing parts, transport parts, high-capacity disk drives, static electricity dissipation home appliances, shielding parts, and oil storage tanks where static electricity generation prevention is essential. , can be used as a material for vehicle parts, etc.

Figure 1 shows a surface resistance measurement area according to an embodiment of the present invention.
Figure 2 is a graph showing the surface resistance value of a conductive composite according to an embodiment of the present invention.

Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. In general, the nomenclature used herein is well known and commonly used in the art.

Throughout this specification, when a part “includes” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary.

In one aspect, the present invention includes a matrix including a first polymer and a second polymer having a higher viscosity than the first polymer; and carbon nanotubes dispersed in the matrix. It provides a PAEK-based conductive composite, characterized in that it has a uniform surface resistance of 10 ³ to 10 ⁹ Ω/sq.

The matrix is a state in which a first polymer and a second polymer with different viscosities are mixed or layered, and the difference in melt volume-flow rate (MVR) of the first polymer and the second polymer is 380 ° C. / 40 to 70 cm3/10 min at 5kg.

Melt volume-flow rate (MVR) is one of the melt indices and represents the volume (cm3/min) extruded for 10 minutes at a constant temperature and a specified force (weight), indicating the fluidity of the polymer material. The higher the molecular weight, the lower the MVR. In other words, the higher the MVR, the better the flowability and the smaller the molecular weight. The present invention relates to a first polymer and a second polymer having different viscosities, that is, a first polymer and a second polymer having a higher viscosity than the first polymer. By controlling the flowability by including in the matrix, not only can the carbon nanotubes be uniformly dispersed in the matrix, but when the composite is manufactured by an extrusion process, the shape of the composite can be maintained without collapsing until it is cooled after extrusion.

Additionally, the difference in melt viscosity between the first polymer and the second polymer is 200 to 1000 Pa·s at 400° C. and a shear rate of 100/s.

Melt viscosity refers to the viscosity of a material in a molten state. Melt viscosity can vary depending on molecular structure, degree of polymerization, etc., and is an important factor directly related to formability. The difference in melt viscosity between the first polymer and the second polymer of the present invention is 200 to 1000 Pa·s at 400°C and a shear rate of 100/s to enable uniform dispersion and extrusion of carbon nanotubes. If the viscosity is outside the above range, the carbon nanotubes may not be uniformly dispersed and thus may not exhibit uniform dispersion resistance, or there may be a problem of the carbon nanotubes not maintaining their shape and collapsing after extrusion due to excessive flowability.

The first polymer and the second polymer may be in the same or different form selected from pellets and powders, and may be selected taking into account the type of polymer, molecular weight, MVR, composite manufacturing method, etc.

Additionally, the first polymer and the second polymer may be the same or different thermoplastic resins.

The first polymer and the second polymer are thermoplastic resins, for example, polycarbonate resin, polypropylene resin, polyamide resin, aramid resin, aromatic polyester resin, polyolefin resin, polyester carbonate resin, polyphenylene ether resin, poly Phenylene sulfide resin, polysulfone resin, polyethersulfone resin, polyarylene resin, cycloolefin resin, polyetherimide resin, polyacetal resin, polyvinyl acetal resin, polyketone resin, polyether ketone resin, polyether ketone Ketone resin, polyetheretherketone resin, polyaryletherketone resin, polyarylketone resin, polyethernitrile resin, liquid crystal resin, polybenzimidazole resin, polyparavanic acid resin, aromatic alkenyl compound, methacrylic acid ester, acrylic acid Vinyl polymer or copolymer resin, diene-aromatic alkenyl compound copolymer resin, vinyl cyanide-diene-aromatic alkenyl obtained by polymerizing or copolymerizing one or more vinyl monomers selected from the group consisting of esters and vinyl cyanide compounds. Compound copolymer resin, aromatic alkenyl compound-diene-vinyl cyanide-N-phenylmaleimide copolymer resin, vinyl cyanide-(ethylene-diene-propylene (EPDM))-aromatic alkenyl compound copolymer resin, polyolefin, vinyl chloride It may be at least one selected from the group consisting of resin and chlorinated vinyl chloride resin, preferably a PAEK-based polymer, and more preferably a polyetheretherketone resin. However, the first polymer and the second polymer are not limited thereto and may be appropriately selected depending on the intended use.

In addition, in the conductive composite, the first polymer and the second polymer are mixed in a ratio of 25 to 80: 20 to 75 or 20 to 75: 25 to 80 based on the weight percent ratio, and if the mixing ratio exceeds the above mixing ratio, the conductivity Difficulties may arise in manufacturing the composite or carbon nanotubes may not be uniformly included in an appropriate amount, which may cause a decrease in surface resistance.

Carbon nanotubes exhibit very high rigidity and strength because they form sp2 bonds between carbon and carbon, and exhibit very low electrical resistance values due to their one-dimensional structure and graphite's unique electrical structure.

In the present invention, the carbon nanotube may be single-walled (SW), double walled (DW), or multi-walled carbon nanotube (MWNT), and may be used as an armchair, zigzag, It may be in the form of chiral, etc., and all of these may be applied without special restrictions.

The carbon nanotubes are included in an amount of more than 0.75% by weight and less than 5% by weight based on the total weight of the composite. If the carbon nanotubes are included in an amount of 0.75% by weight or less, the surface resistance increases to more than 10 ¹⁰ Ω/sq, and if it exceeds 5% by weight, the carbon nanotubes cannot be uniformly dispersed due to agglomeration and compared to the amount added. The degree of increase in conductivity is not large, so economic feasibility is reduced.

Therefore, the carbon nanotubes are included in an amount of more than 0.75% by weight and less than 5% by weight, preferably 1 to 3% by weight, and more preferably 1 to 2% by weight, based on the total weight of the composite.

The surface resistance of the composite of the present invention is 10 ³ to 10 ⁹ Ω/sq, the coefficient of variation of the surface resistance is 0.01 to 0.08, and has a uniform surface resistance.

The coefficient of variation is the standard deviation divided by the arithmetic mean, also called relative standard deviation (RSD), and is used to exclude the influence of the average when comparing standard deviations between measured values. It is used for.

In the present invention, the coefficient of variation is a value obtained by dividing the standard deviation of surface resistance by the average value of surface resistance. The larger the value of the coefficient of variation, the greater the difference in relative values of the data. That is, the coefficient of variation regarding the surface resistance of the present invention is relatively low, 0.01 to 0.08, and the surface resistance of the composite is uniformly distributed.

In addition, since the surface resistance of the composite of the present invention is 10 ³ to 10 ⁹ Ω/sq, it can exhibit conductivity, electromagnetic shielding, ESD, and antistatic performance. Preferably, the surface resistance of the composite is 10 ⁴ to 10 ⁶ Ω. It is assumed to be /sq.

The surface resistance can be measured by the ESD S11.13 (2Pin) or ESD S11.11 (circular) method.

As another example, the present invention includes the steps of melting and mixing a first polymer and carbon nanotubes in a first extruder to produce a masterbatch; and mixing the masterbatch with a second polymer having a higher or lower viscosity than the first polymer in a second extruder to produce a composite.

In the present invention, the step of preparing the masterbatch is a step of melting and mixing the polymer and carbon nanotubes in an extruder to produce a masterbatch in which carbon nanotubes, which are active materials, are concentrated. The polymer is 95 to 99% based on the total weight of the masterbatch. % by weight and 1 to 5 wt% of carbon nanotubes are included to maintain the work efficiency of the masterbatch while manufacturing carbon nanotubes in an agglomerated solid form to improve dispersibility and ensure sufficient carbon nanotubes are included.

The carbon nanotubes are included in an amount of 1 to 5% by weight based on the total weight of the masterbatch. If the carbon nanotubes are included in less than 1% by weight, sufficient electrical conductivity cannot be exhibited, and if the carbon nanotubes are included in more than 5% by weight, the carbon nanotubes cannot be uniformly dispersed due to agglomeration, the workability of the masterbatch deteriorates, and compared to the amount added, the carbon nanotubes cannot be uniformly dispersed. The degree of increase in conductivity is not large, so economic feasibility is reduced.

Therefore, the carbon nanotubes are included in an amount of 1 to 5% by weight, preferably 2 to 3% by weight, based on the total weight of the masterbatch.

The next step is to prepare a composite by mixing the prepared masterbatch with a second polymer having a higher or lower viscosity than the first polymer in a second extruder, and the masterbatch and the second polymer are melt mixed or dried. It can be blended, and the masterbatch:second polymer is mixed in a ratio of 30 to 80:20 to 70 based on weight percent.

The masterbatch: If the second polymer is outside the mixing ratio range of 30 to 80:20 to 70 based on weight% and the mixing ratio of the masterbatch is less than 30 and the mixing ratio of the second polymer is more than 70, an excessive amount relative to the CNT content is used. As polymers are mixed, a conductive composite with a sufficient CNT content cannot be manufactured and therefore cannot exhibit appropriate surface resistance characteristics. In this case, it may be considered to increase the CNT content of the masterbatch to 5% by weight or more to ensure that a sufficient CNT content is included in the conductive composite. However, when the masterbatch is manufactured to contain more than 5% by weight of CNT, the strand (the molten composite discharged into the die) is broken between operations, making it difficult or impossible to manufacture the masterbatch, making it difficult to manufacture a conductive composite. I can't.

In addition, when the mixing ratio of the masterbatch is greater than 80 and the mixing ratio of the second polymer is less than 20, the conductive composite contains a relatively low amount of the second polymer, showing the effect of improving physical properties due to the difference in viscosity between the first polymer and the second polymer. I can't.

In this way, the masterbatch and the second polymer are mixed at a weight percent ratio of 30 ~ 80:20 ~ 70, and the flowability is adjusted due to the melt volume flow index and melt viscosity difference formed by polymers with different viscosities, so that the carbon nanotubes are uniform. It can be dispersed in a matrix containing the first polymer and the second polymer, and the resulting composite can have uniform surface resistance.

At this time, the difference in melt volume-flow rate (MVR) is 40 to 70 cm3/10 min at 380 ℃/5kg, and the difference in melt viscosity is 200 to 1000 Pa·s at 400 ℃ and shear rate of 100/s. , specifically, the first polymer and the second polymer may be the same or different materials and may be in powder form or pellet form, but this is not limited to being appropriately selected depending on the purpose.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited by the examples.

<Example>

Conductive composite fabrication

Example 1

First, the primary polymer was powdered low-viscosity PEEK (VESTAKEEP 2000P evonik) with an MVR of 70cm ³ /10min dried at 130°C for more than 4 hours, and the powdered low-viscosity PEEK of 97.0% by weight and carbon nanotubes ( LG Chem) 3.0 Weight percent is extruded from a twin-screw extruder (temperature conditions in the order of Head > 1~7 Zone: 365-365-365-365-370-375-375-360 ℃) and then pelletized to produce 3.0 weight of carbon nanotubes. A masterbatch (M/B) containing % was prepared.

Afterwards, the prepared masterbatch and the secondary polymer, pellet-type high-viscosity PEEK (VESTAKEEP 4000G evonik) of MVR 11 cm ³ /10 min, were mixed at a weight ratio (% by weight) of 50:50 and extruded using an extruder. A conductive composite was prepared by mixing and extruding under the same conditions as for masterbatch production.

The prepared conductive composite contained 1.5% by weight of carbon nanotubes based on the total weight.

Example 2

When producing the masterbatch, a conductive composite was prepared in the same manner as Example 1, except that pellet-shaped low-viscosity PEEK (VESTAKEEP 2000G evonik) was used as the primary polymer.

Example 3

Example 1 and except that powder-type, high-viscosity PEEK (VESTAKEEP 4000P evonik) was used as the primary polymer for the masterbatch, and pellet-type, low-viscosity PEEK (VESTAKEEP 2000G evonik) was used as the secondary polymer. A conductive composite was prepared in the same manner.

Example 4

Example 1, except that pellet-type, high-viscosity PEEK (VESTAKEEP 4000G evonik) was used as the primary polymer for the masterbatch, and pellet-type, low-viscosity PEEK (VESTAKEEP 2000G evonik) was used as the secondary polymer. A conductive composite was prepared in the same manner.

Example 5

First, the primary polymer for masterbatch was powdered low-viscosity PEEK (VESTAKEEP 2000P evonik) dried at 130°C for more than ⁴ hours, and 98.0% by weight of the primary polymer and 2.0% by weight of CNT were mixed with Twin. -Extruded in a screw extruder (temperature conditions in the order of Head > 1~7 Zone: 365-365-365-365-370-375-375-360 ℃) and then pelletized to produce carbon nanotubes containing 2.0% by weight. A masterbatch (MB) was prepared.

Afterwards, the prepared masterbatch (MB) and the secondary polymer, pellet-type high-viscosity MVR 11 cm ³ /10 min PEEK (VESTAKEEP 4000G evonik) were mixed at a weight ratio (% by weight) of 50:50 and extruded. A conductive composite was prepared by mixing and extruding under the same conditions as the masterbatch preparation.

Carbon nanotubes were included at 1.0% by weight based on the total weight of the prepared conductive composite.

Example 6

A conductive composite containing 1.0% by weight of carbon nanotubes based on the total weight of the composite was prepared in the same manner as in Example 5, except that the primary polymer was 98.5% by weight and CNT was 1.5% by weight when producing the master batch. The carbon nanotube content of the batch was set to 1.5% by weight, and the mixing ratio of the masterbatch and secondary polymer was set to 66:33.

Accordingly, a conductive composite containing 1.0% by weight of CNTs was prepared.

Example 7

A conductive composite containing 1.0% by weight of carbon nanotubes based on the total weight of the composite was prepared in the same manner as in Example 5, but the master batch was prepared by setting the primary polymer at 97% by weight and CNT at 3.0% by weight. The carbon nanotube content of the batch was set to 3.0%, and the mixing ratio of the masterbatch and secondary polymer was set to 33:66.

Accordingly, a conductive composite containing 1.0% by weight of CNTs was prepared.

Example 8

A conductive composite was prepared in the same manner as in Example 5, except that the mixing ratio of the masterbatch and the secondary polymer was 62.5:37.5, and the CNT content of the conductive composite was 1.25% by weight.

Example 9

A conductive composite was prepared in the same manner as in Example 5, except that the mixing ratio of the masterbatch and the secondary polymer was 75:25 and the CNT content of the conductive composite was 1.5% by weight.

Example 10

A conductive composite was prepared in the same manner as in Example 5, except that when preparing the masterbatch, the primary polymer was 97.5% by weight and CNT was 2.5% by weight, so that the CNT content of the masterbatch was 2.5% by weight.

Accordingly, a conductive composite containing 1.25% by weight of CNTs was prepared.

Comparative Example 1

98.5% by weight of pellet-type low-viscosity PEEK (VESTAKEEP 2000G evonik) and 1.5% by weight of carbon nanotubes (LG Chemical) were melt-mixed and extruded in a twin-screw extruder.

Comparative Example 2

It was manufactured in the same manner as Comparative Example 1, except that pellet-type, high-viscosity PEEK (VESTAKEEP 4000G evonik) was used.

Comparative Example 3

A conductive composite containing 1.0% by weight of carbon nanotubes based on the total weight of the composite was prepared in the same manner as in Example 5, except that the primary polymer was 95% by weight and CNT was 5.0% by weight when preparing the master batch. The carbon nanotube content of the masterbatch was set to 5.0%, and the mixing ratio of the masterbatch and secondary polymer was set to 20:80.

Comparative Example 4

A conductive composite was prepared in the same manner as in Example 5, except that the mixing ratio of the masterbatch and the secondary polymer was 25:75 and the CNT content of the conductive composite was 0.5% by weight.

Comparative Example 5

A conductive composite was prepared in the same manner as in Example 5, except that the mixing ratio of the masterbatch and the secondary polymer was 37.5:62.5, and the CNT content of the conductive composite was 0.75% by weight.

Comparative Example 6

A conductive composite was prepared in the same manner as in Example 5, except that when preparing the masterbatch, the primary polymer was 99.0% by weight and the CNT was 1.0% by weight, so that the CNT content of the masterbatch was 1.0% by weight.

Accordingly, a conductive composite containing 0.5% by weight of CNTs was prepared.

Comparative Example 7

A conductive composite was prepared in the same manner as in Example 5, except that when preparing the masterbatch, the primary polymer was 98.5% by weight and CNT was 1.5% by weight, so that the CNT content of the masterbatch was 1.5% by weight.

Accordingly, a conductive composite containing 0.75% by weight of CNTs was prepared.

2. Surface resistance of composite

The surface resistance of the prepared conductive composite was measured by the following method.

Surface resistance measurement method

Figure 1 shows the surface resistance measurement area according to an embodiment of the present invention, in which a 30 cm × 7 cm sample was divided into 140 measurement points (20 × 7) measuring 1.5 cm wide × 1 cm long. Surface resistance was measured at 140 points in the outer surface direction based on the roll. Specifically, a 2Pin type surface resistance meter (PRS-801B, Prostat Corporation) was used to measure horizontal resistance in an environment of 24°C and RH 50 to 60% (based on thermohygrometer).

(1) Surface resistance of conductive composite according to MVR difference

The average surface resistance and coefficient of variation were measured for Examples 1 to 4 and Comparative Examples 1 and 2 prepared above, and are shown in Table 1 and Figure 2 below.

Masterbatch (MB) Secondary polymer (secondary) MB:2nd
Mixing ratio
(weight%) conductive complex primary polymer CNT content in MB
(weight%) MVR viscosity form MVR viscosity form MVR car
( ㎤/10 min) CNTs
content
(weight%) average
surface resistance
(Ω/sq) coefficient of variation Example 1 70 low viscosity powder 3.0 11 high viscosity pellet 50:50 59 1.5 1.5E+4 0.021 Example 2 70 low viscosity pellet 3.0 11 high viscosity pellet 50:50 59 1.5 3.3E+4 0.057 Example 3 11 high viscosity powder 3.0 70 low viscosity pellet 50:50 59 1.5 2.0E+4 0.041 Example 4 11 high viscosity pellet 3.0 70 low viscosity pellet 50:50 59 1.5 1.0E+5 0.037 Comparative Example 1 70 low viscosity pellet - - - - - - 1.5 1.2E+4 0.038 Comparative Example 2 11 high viscosity pellet - - - - - - 1.5 2.1E+9 0.097

Through Table 1 and Figure 2, it can be seen that the composites except Comparative Example 2 exhibit relatively uniform surface resistance.

However, the composite of Comparative Example 1 has excellent flowability as it uses only a low-viscosity polymer and is suitable for injection, but is not suitable for extrusion, where the shape must be maintained without collapsing until cooled after extrusion.

On the other hand, in the case of Examples 1 to 4 where low-viscosity and high-viscosity polymers are mixed, the surface resistance is relatively uniform, and the coefficient of variation of surface resistance is in the range of 0.021 to 0.057.

(2) (If the CNT content of the conductive composite is the same) Surface resistance of the conductive composite according to the mixing ratio of the masterbatch and secondary polymer

The average surface resistance and coefficient of variation of Examples 5 and 6 and Comparative Examples 3 and 4 were measured and are shown in Table 2 below.

Masterbatch (MB) Secondary polymer (secondary)

MB:2nd
Mixing ratio
(weight%) conductive complex note primary polymer CNT content of MB
(weight%) MVR viscosity form MVR viscosity form MVR car
( ㎤/10 min) CNTs
content
(weight%) average
surface resistance
(Ω/sq) Variance
Coefficient Example 5 70 low viscosity powder 2.0 11 high viscosity pellet 50:50 59 1.0 8.1E+5 0.014 Example 6 70 low viscosity powder 1.5 11 high viscosity pellet 66:33 59 1.0 5.7E+5 0.015 Example 7 70 low viscosity powder 3.0 11 high viscosity pellet 33:66 59 1.0 1.1E+6 0.014 Comparative Example 3 70 low viscosity powder 5.0 11 high viscosity pellet 20:80 59 1.0 - M/B
poor work

From Table 2 above, it can be seen that even if the CNT content of the conductive composite is the same, the surface resistance of the conductive composite changes depending on the mixing ratio of the masterbatch and the secondary polymer.

When the mixing ratio of masterbatch and secondary polymer was 33~66:66~33, the average surface resistance was about E+6 Ω/sq.

On the other hand, in Comparative Example 3, the mixing ratio of the masterbatch and the secondary polymer was 20:80, and as the content of the secondary polymer was excessively high, the CNT of the masterbatch when manufacturing a conductive composite having the same CNT content as Examples 5 to 7. There is a need to increase the content. However, when the masterbatch is manufactured so that the CNT content is 5.0% by weight, the strand (the strand of the molten compound discharged into the die) between operations is continuously broken, making masterbatch work impossible.

(3) Surface resistance of conductive composite according to CNT content

(3)-1 (Same CNT content as MB) CNT content and surface resistance of conductive composite according to mixing ratio of masterbatch and secondary polymer

The average surface resistance and variometer of Examples 5, 8, and 9 and Comparative Examples 4 and 5 were measured and are shown in Table 3 below.

Masterbatch (MB) Secondary polymer (secondary) MB:2nd
Mixing ratio
(weight%) conductive complex primary polymer CNT content of MB
(weight%) MVR viscosity form MVR viscosity form MVR car
(㎤/10 min) CNTs
content
(weight%) average
surface resistance
(Ω/sq) Variance
Coefficient Example 5 70 low viscosity powder 2.0 11 high viscosity pellet 50:50 59 1.0 8.1E+5 0.014 Example 8 70 low viscosity powder 2.0 11 high viscosity pellet 62.5:37.5 59 1.25 5.5E+4 0.022 Example 9 70 low viscosity powder 2.0 11 high viscosity pellet 75:25 59 1.5 1.0E+4 0.033 Comparative Example 4 70 low viscosity powder 2.0 11 high viscosity pellet 25:75 59 0.5 7.1E+12 0.015 Comparative Example 5 70 low viscosity powder 2.0 11 high viscosity pellet 37.5:62.5 59 0.75 5.3E+12 0.019

Through Table 3, when the conductive composite contains 1.0 to 1.5% by weight of CNTs, the average surface resistance is 10 ⁺⁴ to 10 ⁺⁶ Ω/sq on average, while the conductive composite contains 0.75% by weight or less of CNTs. When included, it can be confirmed that the average surface resistance is more than 10 ⁺¹¹ Ω/sq.

Additionally, from the above results, it can be seen that the CNT content of the conductive composite and thus the surface resistance change depending on the mixing ratio of the masterbatch and the secondary polymer.

(3)-2 CNT content and surface resistance of conductive composite according to CNT content of masterbatch

The average surface resistance and coefficient of variation were measured for Examples 1, 5, and 10 and Comparative Examples 6 and 7, and are shown in Table 4 below.

Masterbatch (MB) Secondary polymer (secondary) MB:2nd
Mixing ratio
(weight%) conductive complex primary polymer CNT content in MB
(weight%) MVR viscosity form MVR viscosity form MVR car
( ㎤/10 min) CNTs
content
(weight%) average
surface resistance
(Ω/sq) Variance
Coefficient Example 5 70 low viscosity powder 2.0 11 high viscosity pellet 50:50 59 1.0 8.1E+5 0.014 Example 10 70 low viscosity powder 2.5 11 high viscosity pellet 50:50 59 1.25 1.4E+6 0.012 Example 1 70 low viscosity powder 3.0 11 high viscosity pellet 50:50 59 1.5 1.5E+4 0.021 Comparative Example 6 70 low viscosity powder 1.0 11 high viscosity pellet 50:50 59 0.5 3.5E+12 0.013 Comparative Example 7 70 low viscosity powder 1.5 11 high viscosity pellet 50:50 59 0.75 8.2E+11 0.023

In Table 4, when the conductive composite contains 1.0 to 1.5% by weight of CNTs, the average surface resistance is 10 ⁺⁴ to 10 ⁺⁶ Ω/sq on average, whereas the conductive composite contains 0.75% by weight or less of CNTs. In this case, it can be confirmed that the average surface resistance is about 10 ⁺¹¹ LogΩ/sq or more.

Claims (9)

a matrix including a first polymer and a second polymer having a higher viscosity than the first polymer; and
Including carbon nanotubes dispersed in the matrix,
A PAEK-based conductive composite, characterized in that it has a uniform surface resistance of 10 ³ to 10 ⁹ Ω/sq.
According to claim 1,
A PAEK-based conductive composite, characterized in that the coefficient of variation of the surface resistance is 0.01 to 0.08.
According to claim 1,
A PAEK-based conductive composite, characterized in that the difference in melt flow rate (MVR) between the first polymer and the second polymer is 40 to 70 cm3/10 min at 380°C/5kg.
According to claim 1,
A PAEK-based conductive composite, characterized in that the difference in melt viscosity between the first polymer and the second polymer is 200 to 1000 Pa·s at 400° C. and a shear rate of 100/s.
According to claim 1,
A PAEK-based conductive composite, wherein the first polymer and the second polymer are in the same or different form selected from pellets and powders.
According to claim 1,
A PAEK-based conductive composite, characterized in that the carbon nanotubes are contained in an amount of more than 0.75% by weight and less than 5% by weight based on the total weight of the conductive composite.
According to claim 1,
A PAEK-based conductive composite, characterized in that the first polymer and the second polymer are mixed in a ratio of 25 to 80:20 to 75 or 20 to 75:25 to 80.
Manufacturing a masterbatch by melting and mixing the first polymer and carbon nanotubes in a first extruder; and
Manufacturing a composite by mixing the masterbatch with a second polymer having a higher or lower viscosity than the first polymer in a second extruder.
According to claim 8,
A method for producing a PAEK-based conductive composite, characterized in that the masterbatch:second polymer is mixed in a ratio of 30 to 80:20 to 70 based on weight%.