KR101154871B1 - Post treatment technology and its formulation for electric thermal conductive carbon nanotube thin film - Google Patents

Abstract

The present invention is a method of significantly improving the physical properties of the carbon nanotube conductive film by performing a post-treatment process using a titanium alkoxide solution and a reaction initiation solution to the carbon nanotube conductive thin film and the conductive thin film formed by the method It relates to a composition. In this method, carbon nanotube conductive films formed by various methods are treated with a titanium alkoxide post-treatment solution and a reaction initiation solution, and carbon nanotubes are decomposed and physically and chemically combined with titanium alkoxide. Because it improves the mechanical and electrical properties of the tube conductive film efficiently, it can be used in various parts or product fields to which carbon nanotubes are applied.

Description

Post treatment technology and its formulation for electric thermal conductive carbon nanotube thin film

The present invention relates to a post-treatment process technology and composition of an electrically and thermally conductive carbon nanotube thin film, and a conductive thin film formed by the method, and more particularly, to a substrate, an electrically or thermally conductive carbon nanotube thin film formed on the substrate. A post-treatment process method of forming a conductive film composed of carbon nanotube-titanium compounds through decomposition of a post-treatment solution composed of titanium alkoxide, physical and chemical bonding reactions to improve physical, chemical and electrical properties; It relates to a composition formed in this way.

The conductive thin film including carbon nanotubes may be coated on a substrate by substituting hydrophilic functional groups on the carbon nanotubes or forming a water-dispersible carbon nanotube solution using an aqueous surfactant, or using carbon nanotubes using an organic solvent. It is formed by a method of dispersing the coating.

The above-described techniques can obtain a carbon nanotube conductive thin film by a relatively simple method, but it is difficult to apply to various products due to low electrical conductivity and poor durability.

Existing prior arts to solve this problem, a method for improving the physical properties of the conductive thin film by replacing a functional group on the carbon nanotubes, a method for adding a specific material to improve the adhesion and durability to the carbon nanotube dispersion solution, Pretreatment coating of a material capable of inducing a chemical reaction or strong physical interaction on the substrate, and a method of top-coating with a specific material after forming a carbon nanotube film. This method has the following characteristics according to its individual method.

The method of substituting functional groups on carbon nanotubes secures the properties of carbon nanotube conductive thin films by inducing chemical / physical bonds between carbon nanotubes and between substrates and carbon nanotubes by substituting specific functional groups for carbon nanotubes chemically. can do.

However, this method may cause a problem of reducing the conductivity of the carbon nanotubes in the process of introducing functional groups into the carbon nanotubes, and the environmental stability is still weak because the carbon nanotubes are exposed to the outside air.

In the case of adding specific chemicals to the carbon nanotube dispersion solution to improve the durability, it is possible to efficiently form a durable conductive film through a single coating process. However, this method may be difficult to maintain the dispersibility of the carbon nanotube dispersion solution, and the problem of reduced conductivity, light transmittance and haze generation due to the thin film remaining of the additive material.

Substrate surface treatment and pre-treatment coating method can obtain high conductivity characteristics while showing relatively excellent thin film durability, but due to external exposure of carbon nanotubes may be weak to external forces and weak environmental safety.

The method of securing the properties of the conductive film by top-coating is advantageous in terms of performance deterioration and environmental stability due to such external forces, but the conductivity of the conductive film may be reduced due to the top-coating.

The method for improving the durability of the carbon nanotube conductive film by the top-coating method includes a carbon nanotube durability improving technology using a metal oxide. It is a technology to improve the durability of the conductive film by forming a carbon nanotube-metal oxide composite through a drying and heating process by coating a sol (sol) of metal alkoxide on the carbon nanotubes. However, such a method may cause a thin film crack and may be coated with a relatively thick insulating metal oxide, so that electrical conductivity in the vertical direction of the thin film may be weak.

Accordingly, an object of the present invention in view of the above-described conventional problems is a simple post-treatment step without a heating step by using a post-treatment step composition material including titanium alkoxide in a conductive film including carbon nanotubes. The present invention provides a post-treatment process method and a composition thereof capable of efficiently improving the electrical conductivity and durability of a conductive thin film.

The composition formed by the electrically thermally conductive carbon nanotube thin film post-treatment process method according to a preferred embodiment of the present invention for achieving the object as described above, the substrate; A carbon nanotube conductive film formed on the substrate; And a compound film formed using a post-treatment solution and a reaction initiation solution including at least one titanium alkoxide on the conductive film and including a carbon nanotube and a titanium compound.

The titanium compound is characterized in that it comprises titanium oxide, the main component of the titanium hydroxide.

The titanium alkoxide (titanium alkoxide) is characterized in that the titanium (oxygen) -oxygen atom-organic substituent (R) structure.

The titanium alkoxide is characterized in that at least one of titanium methoxide, titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide and titanium pentoxide is selected according to the form of the organic substituent (R).

Preferably, the titanium alkoxide is selected from a kind of precipitated titanium compound through decomposition, exchange, substitution, or condensation reaction in contact with the reaction initiation solution.

The reaction initiation solution is characterized in that it comprises any one or more of water, acid, base, alcohol, a polymer material having a -OH functional group and a polymer material having a -COOH functional group.

The compound film is characterized in that formed to a thickness of 50 nm or less.

It characterized in that it further comprises a polymer film formed by coating a polymer material on the compound film.

Here, the polymer material is characterized in that the material having a -COOH, -OH functional group.

Coating the post-treatment solution on the polymer membrane and characterized in that it further comprises a composite membrane formed in contact with the reaction initiation solution.

The substrate is characterized by using any one of glass, quartz, glass wafers, silicon wafers, transparent and opaque plastic substrates, transparent and opaque polymer films.

The conductive layer is characterized in that at least one of a single-walled carbon nanotubes, a functionalized single-walled carbon nanotubes, a double-walled carbon nanotubes, a functionalized double-walled carbon nanotubes, multi-walled carbon nanotubes, functionalized multi-walled carbon nanotubes are used It is done.

According to a preferred embodiment of the present invention, an electrically and thermally conductive carbon nanotube thin film post-treatment method may include preparing a substrate and using a carbon nanotube dispersion solution on the substrate. Forming a conductive film, and forming a compound film including carbon nanotubes and titanium compounds using a post-treatment solution and a reaction initiation solution including at least one titanium alkoxide on the conductive film. Include.

The titanium compound is characterized in that it comprises titanium oxide, the main component of the titanium hydroxide.

The titanium alkoxide is characterized in that the titanium (oxygen) -oxygen atom-organic substituent (R) structure.

The titanium alkoxide is characterized in that at least one of titanium methoxide, titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide and titanium pentoxide is selected according to the form of the organic substituent (R).

The titanium alkoxide may be selected from a kind of precipitated titanium compound through decomposition, exchange, substitution, or condensation reaction in contact with the reaction initiation solution.

The concentration of the titanium alkoxide in the aftertreatment solution is characterized in that less than 30 wt%.

The solvent of the aftertreatment solution is characterized in that the alcohol, such as methanol, ethanol, propanol, isopropanol, butanol and mixtures thereof.

The reaction initiation solution is characterized in that it comprises any one or more of water, acid, base, alcohol, a polymer solution having a -OH functional group and a polymer solution having a -COOH functional group.

The forming of the compound film may be performed by coating the post-treatment solution on the conductive layer and then contacting the reaction starting solution before the post-treatment solution is dried.

The reaction initiation contact method is a dip coating, spray coating, spin coating, solution casting, dropping, roll coating, gravure coating, bar coating ( bar coating).

The method may further include forming a polymer film by coating a polymer material on the compound film.

The polymer material is characterized in that the material having a -COOH, -OH functional group.

The method may further include forming a composite membrane by coating the post-treatment solution on the polymer membrane and contacting the reaction initiation solution.

In the preparing process, before the process of forming the conductive film, the substrate is treated with Piranha solution, acid treatment, base treatment, plasma treatment, atmospheric pressure plasma treatment, ozone treatment, UV treatment, SAM (self assembled monolayer) Treatment, and further comprising the step of performing a surface treatment using at least one of the polymer or monomolecular coating method.

Forming the conductive film may include dip coating, spray coating, spin coating, solution casting, dropping, and rolling the carbon nanotube dispersion solution on the substrate. (roll) coating, characterized in that the coating using any one of the methods such as gravure coating.

The present invention provides a method for greatly improving the electrical conductivity and environmental stability of a conductive thin film including carbon nanotubes by applying a post-treatment process to a previously formed conductive thin film. The material used in the post-treatment process is a titanium alkoxide material, which forms a strong bond between the conductive thin film and the post-treatment material or between the post-treatment materials by water, alcohol, acid, and base, and thus the electrical conductivity of the conductive thin film. In addition, there is an advantage of greatly improving the environmental stability and greatly improving the physical properties of the conductive thin film. In particular, this method can be easily applied to conductive thin films formed by various methods, and can effectively improve the physical properties of the thin films. Therefore, this method is combined with conductive film forming methods including carbon nanotubes, which are commonly known. The conductive thin film including nanotubes can be applied.

1 to 3 is a view for explaining a composition according to the post-treatment of the electrically, thermally conductive carbon nanotube thin film according to an embodiment of the present invention.
Figure 4 is a flow chart for explaining the electrical and thermally conductive carbon nanotube thin film post-processing method according to an embodiment of the present invention.
5 to 9 are views for explaining a method for post-processing an electrically and thermally conductive carbon nanotube thin film according to an embodiment of the present invention.
10 is a flowchart illustrating a method of post-processing an electrically and thermally conductive carbon nanotube thin film according to a first embodiment of the present invention.
FIG. 11 is a graph illustrating XPS analysis of a titanium compound formed by the process method of FIG. 10.
12 is a SEM photograph of the conductive film and the compound film formed by the process method of FIG.
FIG. 13 is a flowchart illustrating a method of post-processing an electrically and thermally conductive carbon nanotube thin film according to a second embodiment of the present invention. FIG.
14 is a flowchart illustrating a method for processing an electrically and thermally conductive carbon nanotube thin film according to a third embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

First, the composition according to the post-treatment of the electrically, thermally conductive carbon nanotube thin film according to the embodiment of the present invention will be described. 1 to 3 is a view for explaining a composition according to the post-treatment of the electrically, thermally conductive carbon nanotube thin film according to an embodiment of the present invention.

Referring to Figure 1, the composition according to the post-treatment of the electrical, thermally conductive carbon nanotube thin film according to an embodiment of the present invention is formed on the substrate 100, according to the post-treatment process, the carbon nanotube conductive thin film (hereinafter referred to , Abbreviated as "conductive film," 200 to form a compound film (hereinafter, abbreviated as "compound film") 300, which is a composite of carbon nanotubes and a titanium compound, through reaction with a titanium compound. That is, as shown, it has a structure of the substrate 100, the conductive film 200, the compound film 300. Meanwhile, referring to FIG. 2, the composition according to the post-treatment of the electrically and thermally conductive carbon nanotube thin film according to the embodiment of the present invention may further include a polymer film 400 formed on the compound film 300. In addition, referring to FIG. 3, a titanium compound film 500 formed on the polymer film 400 may be further included.

The substrate 100 uses one of glass, quartz, glass wafers, silicon wafers, transparent and opaque plastic substrates, transparent and opaque polymer films, and metals. Piranha solution treatment, acid treatment, base treatment, plasma treatment, atmospheric pressure plasma treatment, ozone treatment, UV treatment, SAM (self assembled monolayer) treatment, and polymer or monomolecule coating method Surface treatment can be performed using at least one of the methods.

The conductive film 200 is formed by coating a carbon nanotube dispersion solution on the substrate 100.

Here, the carbon nanotubes are at least one of single-walled carbon nanotubes, functionalized single-walled carbon nanotubes, double-walled carbon nanotubes, functionalized double-walled carbon nanotubes, multi-walled carbon nanotubes, functionalized multi-walled carbon nanotubes Can be carbon nanotubes.

In addition, the carbon nanotube dispersion solution may use an aqueous surfactant or may generate a dispersion solution using an organic solvent. When using an aqueous surfactant, using an aqueous surfactant such as SDBS, SDS, LDS, CTAB, DTAB, PVP, Triton X-series, Brij-series, Tween-series, poly (acrylic acid), polyvinyl alcohol, etc. desirable. In addition, when using an organic solvent, it is preferable to use the organic solvent comprised from NMP, DMF, DCE, THF, etc. On the other hand, in addition to the above-described aqueous surfactant or organic solvent can be produced carbon nanotube dispersion solution by various other methods. In addition to the above-described aqueous surfactant or organic solvent, various other methods may be used.

The coating may be any one of a method such as dip coating, spray coating, spin coating, solution casting, dropping, roll coating, and gravure coating. Is preferably used.

The compound film 300 is formed by coating the aftertreatment solution on the conductive film 200 and then contacting the reaction starting solution before the aftertreatment solution is dried. The compound film 300 includes a carbon nanotube and a titanium compound, wherein the titanium compound is mainly composed of titanium hydroxide and some titanium oxide may be formed. The compound film 300, which is a thin film of titanium compound formed as described above, is formed to a thickness of 50 nm or less, and results in improving electrical conductivity and environmental stability of the carbon nanotube thin film.

The aftertreatment solution may comprise at least one type of titanium alkoxide material. Titanium alkoxide has a structure of titanium (oxygen atom) -organic substituent (R). In addition, the titanium alkoxide may be selected from at least one of titanium methoxide, titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, and titanium pentoxide, depending on the type of alkoxide functional group. In particular, titanium alkoxide selects a kind of titanium alkoxide which undergoes decomposition and substitution, exchange, condensation, and polymerization reaction by the reaction initiation solution having water, acid, base, alcohol, -OH or -COOH functional group.

When the post-treatment process is performed using the above-described post-treatment solution, the compound film 300 composed of carbon nanotubes and titanium compounds according to physical and chemical reactions between titanium alkoxides or between titanium alkoxides and carbon nanotubes Is formed.

The titanium alkoxide solution in the post-treatment solution is preferably formulated at a concentration of 30 wt.% Or less. In addition, as a solvent of the aftertreatment solution, alcohols such as methanol, ethanol, propanol, isopropanol, butanol, and mixtures thereof may be used. Such solvents are preferably selected from those which do not react with titanium alkoxides or where very slow reactions occur.

The post-treatment solution does not contain any acid and does not react with titanium alkoxide, which is a major constituent, so that no titanium oxide sol is formed. However, a very slow reaction may proceed by a small amount of moisture present in the air or as an impurity in the solvent, but the level does not affect the post-treatment process.

Coating of the aftertreatment solution may include dip coating, spray coating, spin coating, solution casting, dropping, roll coating, gravure coating, and bar coating ( bar coating).

The reaction initiation solution includes at least one of a polymer solution having water, alcohol, acid, base, -OH and -COOH functional groups, and the reaction initiation solution is contacted before the coated aftertreatment solution is dried. That is, after the post-treatment solution coating, when the reaction starter solution is contacted again, titanium alkoxide (titanium oxide) contained in the post-treatment solution reacts with the reaction starter solution material. Accordingly, the titanium compound is fixed on the conductive film 200 which is a carbon nanotube thin film to form a compound film 300 which is a compound composite of carbon nanotubes and titanium. At this time, the contact method of the reaction starting solution is dip coating, spray coating, spin coating, solution casting, dropping, roll coating, gravure coating, and It can be done by either method of bar coating.

In order to achieve the above object, the electrically and thermally conductive thin film post-treatment composition is composed of titanium alkoxide (titanium oxide), and the post-treatment process is performed on the conductive thin film including carbon nanotubes as a post-treatment process composition. By doing so, the physical properties of the conductive thin film can be improved.

Meanwhile, referring to FIG. 2, the polymer film 400 may be further included on the compound film 300 described above. The polymer film 400 is formed by coating a polymer material on the compound film 300. In particular, when a polymer material having -COOH and -OH functional groups is applied as a polymer material, the titanium hydroxide formed during the post-treatment process reacts with -COOH and -OH of the polymer to form a bond of "-tianium-oxygen atom-polymer". The durability of the conductive film can be further enhanced.

In addition, referring to Figure 3, according to an embodiment of the present invention, by repeating the after-treatment process and the polymer coating process of the titanium alkoxide (titanium oxide) solution and the reaction initiation solution can significantly improve the durability of the carbon nanotube thin film have. That is, as described above, the polymer film is further coated on the compound film 300 to form the polymer film 400, or the polymer material is coated on the compound film 300 which is a carbon nanotube-titanium compound thin film. After the polymer film 400 is formed, the composite film 500 may be further formed by further performing a post-treatment process of an alkoxide solution and a reaction initiation solution.

Next, a method of post-processing an electrically and thermally conductive carbon nanotube thin film according to an embodiment of the present invention will be described.

4 is a flowchart illustrating a method of post-processing an electrically and thermally conductive carbon nanotube thin film according to an embodiment of the present invention, and FIGS. 5 to 9 are electrically and thermally conductive carbon nanotube thin films according to an embodiment of the present invention. It is a figure for demonstrating the post-processing process method.

Referring to FIG. 4, the substrate 100 is prepared in step S401. This is illustrated in FIG. 5. The substrate 100 may use any one of glass, quartz, glass wafers, silicon wafers, transparent and opaque plastic substrates, transparent and opaque polymer films, and metals. Then, surface treatment is optionally performed on the substrate 100 in step S403. Using at least one of Piranha solution treatment, acid treatment, base treatment, plasma treatment, atmospheric plasma treatment, ozone treatment, UV treatment, self assembled monolayer (SAM), and polymer or monomolecular coating methods Surface treatment can be performed.

Then, using the carbon nanotube dispersion solution on the substrate 100 in step S405 to form a conductive film 200 including carbon nanotubes. 6 illustrates a state in which the conductive film 200 is formed on the substrate 100.

Here, the carbon nanotubes are at least one of single-walled carbon nanotubes, functionalized single-walled carbon nanotubes, double-walled carbon nanotubes, functionalized double-walled carbon nanotubes, multi-walled carbon nanotubes, functionalized multi-walled carbon nanotubes Can be carbon nanotubes.

The carbon nanotube dispersion solution may use an aqueous surfactant or may generate a dispersion solution using an organic solvent. When using an aqueous surfactant, using an aqueous surfactant such as SDBS, SDS, LDS, CTAB, DTAB, PVP, Triton X-series, Brij-series, Tween-series, poly (acrylic acid), polyvinyl alcohol, etc. desirable. In addition, when using an organic solvent, it is preferable to use the organic solvent comprised from NMP, DMF, DCE, THF, etc. On the other hand, in addition to the above-described aqueous surfactant or organic solvent can be produced carbon nanotube dispersion solution by various other methods. As described above, after the carbon nanotube dispersion solution is generated, the conductive film 200 is formed by coating the dispersion solution on the upper surface of the substrate 100. In this case, the coating may be any one of dip coating, spray coating, spin coating, solution casting, dropping, roll coating, and gravure coating. It is preferably carried out using the method of.

Subsequently, in step S407, the conductive film 200 is washed with water to remove the dispersant. Then, dry the process product in step S409.

Next, in step S411 by using a post-treatment solution and the reaction starting solution to form a compound film 300 made of a compound of carbon nanotubes and titanium (titanium) on the conductive film (200). 7 shows a state in which the compound film 300 is formed.

Titanium alkoxide constituting the aftertreatment solution has a structure of titanium (oxygen) -oxygen atom-organic substituent (R). In addition, the titanium alkoxide may be selected from at least one of titanium methoxide, titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, and titanium pentoxide, depending on the type of alkoxide functional group. In particular, titanium alkoxides are selected from titanium alkoxides of the kind in which decomposition and substitution, exchange, condensation, and polymerization reactions occur by contact with water, acid, base, and alcohol by -OH or -COOH functional groups.

When the post-treatment process is performed using the above-described post-treatment solution, a compound film 300 composed of carbon nanotubes and titanium compounds according to physical and chemical reactions between titanium alkoxides or between titanium alcohols and carbon nanotubes ) Is formed.

The titanium alkoxide solution in the post-treatment solution is preferably formulated at a concentration of 30 wt.% Or less. The aftertreatment solution may also include at least one kind of titanium alkoxide material. In addition, as a solvent of the aftertreatment solution, alcohols such as methanol, ethanol, propanol, isopropanol, butanol, and mixtures thereof may be used.

The post-treatment solution does not contain any type of acid, so that the reaction of titanium alkoxide, which is a major component, does not occur. However, although the reaction may be very slow due to moisture in the air, it does not affect the post-treatment process.

The aftertreatment solution is dip coated, spray coated, spin coated, solution casting, dropping, roll coating, and gravure onto the conductive film 200. Coating is carried out by any one of coating and bar coating.

As described above, after the aftertreatment solution is coated on the conductive layer 200, the alcohol and water which can react with the titanium alkoxide material contained in the aftertreatment solution before the coated aftertreatment solution is dried , The compound film 300 is formed on the conductive film 200 by contact with a reaction initiation solution such as a polymer solution having at least one of an acid, a base, a -OH, and a -COOH functional group. That is, after the post-treatment solution coating, when the reaction starting solution is again coated, the titanium compound is fixed on the conductive film 200 which is a carbon nanotube thin film to form a compound film 300 which is a compound composite of carbon nanotubes and titanium. do. At this time, the contact method of the reaction starting solution is dip coating, spray coating, spin coating, solution casting, dropping, roll coating, gravure coating, and It can be done by either method of bar coating.

After the compound film 300 is formed, the substrate product on which the compound film is formed is washed in step S413, and dried in step S415.

The compound film 300 formed by the above-described method may include some titanium oxide mainly based on titanium hydroxide. In addition, the compound film 300 is formed to a thickness of 50 nm or less. The compound film 300 shows a result of improving the electrical conductivity and environmental stability of the carbon nanotube thin film.

Meanwhile, in operation S417, a polymer material is further coated on the compound film 300 to form the polymer film 400. Here, when the polymer material having -COOH, -OH functional group is applied as the polymer material, the titanium hydroxide formed during the post-treatment process of the titanium alkoxide solution and the reaction initiation solution reacts with -COOH, -OH of the polymer. By forming a bond of "-tianium-oxygen atom-polymer", the durability of the conductive film can be further enhanced. This is illustrated in FIG. 8.

In addition, according to an embodiment of the present invention, the durability of the carbon nanotube thin film can be significantly improved by repeating the aftertreatment process and the polymer coating process of the titanium alkoxide solution and the reaction initiation solution. That is, as described above, the polymer film 400 is further coated on the compound film 300 to form the polymer film 400, or as described above, the compound film is a carbon nanotube-titanium compound thin film as in step S417. After coating the polymer material on the 300, the polymer film 400 is formed, and then the composite film 500 is further formed by further performing a post-treatment process using a titanium alkoxide solution and a reaction initiation solution in step S419. By doing so, the durability can be greatly improved. 9 shows the composite film 500 is formed.

Next, specific embodiments of the present invention will be described, and thus the effects of the present invention will be described.

First embodiment

10 is a flowchart illustrating a method of post-processing an electrically thermally conductive carbon nanotube thin film according to a first embodiment of the present invention.

5 to 7 and 10, as shown in FIG. 5 in step S1001, a soda lime glass substrate 100 is prepared. Next, in step S1003, a conductive film 200 including carbon nanotubes is formed on the substrate 100 using a dispersion solution. This is illustrated in FIG. 6.

Here, the dispersion solution is produced by adding a single-walled carbon nanotube and a sodium dodecylbenzenesulfonate (SDBS) dispersant to water and using an ultrasonic disperser. In addition, the conductive film 200 is produced by coating the substrate surface with a spray coating apparatus using a dispersion solution. Then, the dispersant is removed by performing a washing process with water in step S1005, and dried at room temperature for 60 minutes in step S1007, the measured sheet resistance of the carbon nanotube conductive film 200 has a value of 620 Ω / sq.

Subsequently, in step S1009, a carbon nanotube conductive film is subjected to a post-treatment process to form a compound film 300 of carbon nanotube-titanium compounds. This is illustrated in FIG. 7. The ethanol solution of 0.5 wt% titanium ethoxide was used as a post-treatment solution, and the carbon nanotube-coated substrate was dip coated on the post-treatment solution, and then dipped in water immediately before drying. The compound film 300, which is a carbon nanotube-titanium composite thin film, was formed. And sufficiently washed with water in step S1011, dried at room temperature for 60 minutes in step S1013, the sheet resistance was measured to obtain a sheet resistance value of 490 Ω / sq.

For the chemical resistance evaluation of the conductive film 200 including the carbon nanotube-titanium compound formed by the above-described method, the specimen was acetone, toluene, isopropylalcohol, methanol, After immersion in 1-methyl pyrrolidone (1-methyl prrolidone) for 10 minutes, washed with water and dried for 60 minutes to measure the sheet resistance change of the conductive film 200 to obtain the results as shown in Table 1 below.

Chemical resistance evaluation No post-processing Post-processing process Initial sheet resistance
(Ω / aq) Surface resistance after test
(Ω / sq) Initial surface resistance
(Ω / aq) Surface resistance after test
(Ω / sq) acetone 575  598 492 501 ethanol 580 600 472 475 toluene 640 645 563 563 isopropyl alcohol 650 665 551 555 NMP 640 730 570 590

In addition, to evaluate the environmental stability, the change in sheet resistance was measured for 240 hours at a relative humidity of 90 ° and a temperature of 60 ° C., and 90 ° using “3M magic tape”. Peel strength test (90 ° Peel test) was carried out to obtain the results as shown in Table 2 below.

Environmental stability evaluation No post-processing Post-processing process Initial sheet resistance
(Ω / aq) Surface resistance after test
(Ω / sq) Initial surface resistance
(Ω / aq) Surface resistance after test
(Ω / sq) Heat / humidity
resistance
(240hr at 60 ℃)
664
1368
556
654 90 ° Peel test
(3M magic tape,
Cat. 122A)
655
2014
513
582

11 and 12 show the results of the post-treatment method of the electrically and thermally conductive carbon nanotube thin film according to the first embodiment. FIG. 11 is a graph in which the titanium compound formed by the process method of FIG. 10 is analyzed by XPS. 12 is a SEM photograph of the conductive film and the compound film formed by the process method of FIG.

In order to analyze the composition of the titanium compound 300 formed as a result of the post-treatment process, X-ray photoelectron spectroscopy (XPS) was used to analyze the binding energy of the photoelectrons, and the analysis results are shown in FIG. 11. Compound composition was confirmed using Ti2p peak and O1s peak. As shown in FIG. 11, the binding energy of the Ti2p peak of the titanium compound has a value of 548 eV to confirm the presence of Ti4 +, and the type of the titanium compound can be confirmed from the O1s peak (528 to 534 eV). The binding energy of O1s in all titanium compounds is divided into three categories, 529.43 eV in TiO ₂ , 530.60 eV in Ti ₂ O ₃ , and 531.95 eV peak in Ti-OH. And peaks (CO, 532.8 eV) due to the remaining alkoxy groups and peaks (533 eV) due to SiO ₂ on the glass substrate [reference, Thin solod films, 379, (2000), 7-14]. In another previous study, O1s of titanium compounds containing oxygen showed peaks in the range of 528 to 532 eV for oxygen contained in -OH, and 526 to 530 eV for lattice oxygen of titanium oxide without -OH. The results showed peaks in the range [reference, Applied surface science 246 (2005) 239-249].

As shown in FIG. 11, as shown in the XPS analysis, the binding energy of O1s forms the maximum value at 532 eV, and it can be seen that the main component constituting the compound film 300 is titanium hydroxide form from the peak distribution. In addition, it can be seen that residual organic materials including titanium oxide and oxygen are present.

The initial peak of the XPS peak and the change in the peak appearing as the etching proceeds, and as the etching progresses, the Ti2p3 / 2 peak and the O1s peak of the titanium compound disappear and the O1s peak of the SiO ₂ of the substrate glass increases. It can be seen that the titanium compound of (300) is coated on the carbon nanotubes on the conductive film in an ultrathin film state. In general, since the inorganic film is etched by several nm for 1 minute by Ar sputtering, the thickness of the conductive film according to the present invention can be viewed as 10 nm or less. This can be confirmed in the comparison of SEM images of the conductive film 200 and the compound film 300, as shown in FIG. 12, wherein the titanium compound film formed by the post-treatment process is so thin that it is difficult to confirm the SEM image. It is showing.

Second Embodiment

13 is a flowchart illustrating a method of post-processing an electrically thermally conductive carbon nanotube thin film according to a second embodiment of the present invention.

5 to 8 and 13, the PET substrate 100 is prepared in step S1101. This is illustrated in FIG. 5. Thereafter, in step S1103, a conductive film 200 including carbon nanotubes is formed on the substrate 100 using a dispersion solution. 6 shows a state in which the conductive film 200 is formed on the substrate 100.

Here, the carbon nanotube dispersion solution is produced by adding a single-walled carbon nanotube and sodium dodecylbenzenesulfonate (SDBS) dispersant to water and using an ultrasonic disperser. In addition, the conductive film 200 is produced by coating the upper surface of the substrate 100 with a spray coating apparatus using a dispersion solution.

Then, after removing the dispersant by washing with water in step S1105, and dried at room temperature for 60 minutes in step S1107. After drying, the sheet resistance of the measured carbon nanotube conductive film 200 has a value of 640 dl / sq.

Subsequently, a post-treatment process of the carbon nanotube conductive film is performed in step S1109 to form the compound film 300 which is a thin film of the carbon nanotube-titanium compound. FIG. 7 shows that an ultrathin compound film 300 is formed on the conductive film 200. A 0.5 wt% titanium ethoxide ethanol solution was used as the post-treatment solution, and the carbon nanotube-coated substrate was dip coated onto the post-treatment solution, and then immediately dipped in water before drying. To form a carbon nanotube-titanium composite thin film. And sufficiently washed with water in step S1111, and dried at room temperature for 60 minutes in step S1113.

Then, in step S1115 to form an ultra-thin polymer film 400 on the compound film 300 by a layer-by-layer deposition method. 8 shows a state in which the polymer film 400 is formed on the compound film 300. In order to form the polymer film 400, the polymer film 400 is formed by dip coating a 0.5 wt% polyacrylic acid aqueous solution on the compound film 300 for 3 minutes. Then, after washing with water in step S1117, it is dried for 3 hours in step S1119. By measuring the sheet resistance of the composite thin film including the carbon nanotubes completed in this way it is possible to obtain a value of 515 Ω / sq.

In order to evaluate the chemical resistance of the conductive film 200 including the carbon nanotube-titanium compound formed by the above-described method, the specimen was acetone, toluene, isopropylalcohol, methanol, Immerse in 1-methyl pyrrolidone (1-methyl prrolidone) for 10 minutes. After washing with water and drying for 60 minutes, the sheet resistance of the conductive film 200 was measured to obtain a result as shown in Table 3 below.

Chemical resistance evaluation No post-processing Post-processing process Initial sheet resistance
(Ω / aq) Surface resistance after test
(Ω / sq) Initial surface resistance
(Ω / aq) Surface resistance after test
(Ω / sq) acetone 575  598 557 566 methanol 584 606 574 565 toluene 641 647 551 555 isopropyl alcohol 658 665 584 605 NMP 640 732 500 534

In addition, to evaluate the environmental stability, the change in sheet resistance was measured for 240 hours at a relative humidity of 90 ° and a temperature of 60 ° C., and a 90 ° peel test was conducted using a “3M magic tape”. The following results were obtained as shown in Table 4.

Environmental stability evaluation No post-processing Post-processing process Initial sheet resistance
(Ω / aq) Surface resistance after test
(Ω / sq) Initial surface resistance
(Ω / aq) Surface resistance after test
(Ω / sq) Heat / humidity
resistance
(240hr at 60 ℃)
672
1122
534
631 90 ° Peel test
(3M magic tape,
Cat. 122A)
634
1902
557
559

Third embodiment

14 is a flowchart illustrating a method of post-processing an electrically thermally conductive carbon nanotube thin film according to a third embodiment of the present invention.

5 to 9 and 14, as shown in FIG. 5 at step S1201, a PET substrate 100 is prepared.

Next, in step S1203 to form a conductive film 200 including carbon nanotubes using a dispersion solution on the substrate 100. 6 shows a state in which the conductive film 200 is formed on the substrate 100. Here, the dispersion solution is produced by adding a single-walled carbon nanotube and a sodium dodecylbenzenesulfonate (SDBS) dispersant to water and using an ultrasonic disperser. In addition, the conductive film 200 is produced by coating the upper surface of the substrate 100 with a spray coating apparatus using a dispersion solution. Then, after removing the dispersant by performing a washing process with water in step S1205, and dried at room temperature for 60 minutes in step S1207. After drying, the measured sheet resistance of the carbon nanotube conductive film 200 has a value of 610 dl / sq.

Subsequently, in step S1209, the carbon nanotube conductive film is subjected to a post-treatment process to form a compound film 300 of carbon nanotube-titanium compounds. FIG. 7 shows that the compound film 300 is formed on the conductive film 200. A 0.5 wt% titanium ethoxide ethanol solution was used as the post-treatment solution, and the carbon nanotube-coated substrate was dip coated onto the post-treatment solution, and then immediately dipped in water before drying. Thus, the compound film 300, which is a carbon nanotube-titanium composite thin film, is formed. And sufficiently washed with water in step S1211, and dried at room temperature for 60 minutes in step S1213.

Next, an ultra-thin polymer film 400 is formed on the compound film 300 which is a composite thin film by a layer-by-layer deposition method in step S1215. That is, the polymer film 400 is formed by dip coating a 0.5 wt% polyacrylic acid aqueous solution on the compound film 300 for 3 minutes. 8 shows a state in which the polymer film 400 is formed on the compound film 300. Then, washed with water in step S1217, and then dried for 30 minutes in step S1219.

In operation S1221, the composite film 500 is formed on the polymer film 400. 9 shows a composite film 500 formed on the polymer film 400.

In order to form the composite film 500, the carbon nanotube-polymer-titanium composite was immersed in an ethanol solution of 0.5 wt% titanium ethoxide for 20 seconds, and then immersed in water and washed by dipping. A composite film 500 is formed. Then, it is dried for 1 hour in step S1223.

As such, the sheet resistance of the composite thin film including the completed carbon nanotubes has a value of 494 mA / sq.

In order to evaluate the chemical resistance of the conductive film 200 including the carbon nanotube-titanium compound formed by the above-described method, the specimen was acetone, toluene, isopropylalcohol, methanol, Immerse in 1-methyl pyrrolidone (1-methyl prrolidone) for 10 minutes. Then, washed with water and dried for 60 minutes to measure the sheet resistance change of the conductive film 200 to obtain the results as shown in Table 5 below.

Chemical resistance evaluation No post-processing Post-processing process Initial sheet resistance
(Ω / aq) Surface resistance after test
(Ω / sq) Initial surface resistance
(Ω / aq) Surface resistance after test
(Ω / sq) acetone 562  568 541 552 methanol 574 570 575 565 toluene 633 645 580 567 isopropyl alcohol 642 665 588 602 NMP 634 680 523 537

In addition, to evaluate the environmental stability, the change in sheet resistance was measured for 240 hours at a relative humidity of 90 ° and a temperature of 60 ° C., and a 90 ° peel test was conducted using a “3M magic tape”. The following results were obtained as shown in Table 6.

Environmental stability evaluation No post-processing Post-processing process Initial sheet resistance
(Ω / aq) Surface resistance after test
(Ω / sq) Initial surface resistance
(Ω / aq) Surface resistance after test
(Ω / sq) Heat / humidity
resistance
(240hr at 60 ℃)
675
1204
538
579 90 ° Peel test
(3M magic tape,
Cat. 122A)
639
1785
555
551

The aftertreatment solution according to the embodiment of the present invention as described above does not contain any kind of acid so that the sol of titanium alkoxide is not formed in the solution, and less than 10 wt% of titanium alkoxide is dissolved in a solvent such as alcohol. maintain. In particular, the present invention is coated with a post-treatment solution containing titanium alkoxide, the reaction initiation solution, such as water, acid, base, alcohol, polymer solution having a -OH or -COOH functional group that can react with titanium alkoxide Contact with the formed titanium alkoxide coating film. This method allows the titanium alkoxide to react instantaneously on the carbon nanotube thin film to form a conductive composite thin film containing titanium hydroxide. When the compound film 300, which is a carbon nanotube-titanium compound composite, is formed using titanium ethoxide, the present invention shows that the electrical resistance is increased, and the sheet resistance value is reduced by about 20% compared with the post-treatment process. .

The composition formed through the post-treatment process may be further improved in properties by an additional process. Further increase in durability may be expected by forming the polymer film 400 on the compound film 300 through a titanium alkoxide post-treatment process.

The method of forming the polymer coating film may include dip coating, spray coating, spin coating, solution casting, dropping, roll coating, gravure coating, and bar coating ( bar coating) is applicable. A variety of commercially available polymers can be applied, and in particular, a polymer capable of growing a layer-by-layer thin film through hydrogen bonding or chemical bonding with -OH functional groups of titanium hydroxide present in a carbon nanotube-titanium compound thin film, namely After coating a polymer having a -OH or -COOH functional group by a dip-coating method, the composite thin film may be washed with a solvent of the polymer to form a thin and ultra thin polymer ultrathin film on the compound film 300.

In addition, when performing the post-treatment process of the titanium alkoxide solution and the reaction starting solution again on the polymer film 400 of the carbon nanotube-titanium compound-polymer composition thus formed, further durability improvement can be expected. In addition to the formation of additional titanium compounds on the polymer film 400 by the above-described post-treatment process, -OH, -COOH and titanium alkoxide of the post-treatment solution react with each other during the post-treatment solution coating process to react with "titanium- This is because the polymer is crosslinked by forming an oxygen atom-polymer "bond. Repeated treatment of the titanim alkoxide solution and the reaction initiation solution and the polymer coating process can form a composition having improved durability.

The conductive film formed by the method of the present invention as described above is of high quality with improved physical properties, and can be applied to various parts such as transparent electrodes, surface heating elements, electrostatic control and absorbents, electromagnetic shielding films, and heat radiation materials by excellent durability and high conductivity. Can be.

Although the content of the present invention has been described as described above, the scope of the present invention is not limited to the above content. The present invention can be applied to all conductive films formed according to various pretreatment methods, carbon nanotube types, and carbon nanotube coating methods. In addition to the titanium alkoxide materials described above, the present invention is coated on the carbon nanotube conductive films by a solution process method. Titanium alkoxide material is then reacted within seconds by the reaction initiation solution such as water, alcohol, acid, base, polymer solution having -OH or -COOH, which is continuously contacted, to form a carbon nanotube-titanium compound complex. Included.

As described above, in the detailed description of the present invention has been described with respect to specific embodiments, various modifications are possible without departing from the scope of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below, but also by the equivalents of the claims.

100: substrate
200: conductive film
300 compound film
400: polymer membrane
500: composite membrane

Claims (27)

In the composition formed by the electrically, thermally conductive carbon nanotube thin film post-treatment process method,
Board;
A carbon nanotube conductive film formed on the substrate; And
Compound formed on the conductive film by using a post-treatment solution and a reaction initiation solution containing at least one titanium alkoxide (titanium alkoxide), including carbon nanotubes and titanium compounds, formed to a thickness of more than 0 and 50 nm or less A composition formed by an electrically, thermally conductive carbon nanotube thin film post-treatment process method comprising a film. The method of claim 1, wherein the titanium compound
A composition formed by an electrical, thermally conductive carbon nanotube thin film post-treatment process method comprising titanium hydroxide and titanium oxide. The method of claim 1, wherein the titanium alkoxide is
A composition formed by a post-treatment method of an electrically, thermally conductive carbon nanotube thin film, characterized in that the titanium (oxygen) -oxygen atom-organic substituent (R) structure. The method of claim 1, wherein the titanium alkoxide is
According to the form of the organic substituent (R), at least one of titanium methoxide, titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, titanium pentoxide is selected. Formed by the composition. In the composition formed by the electrically, thermally conductive carbon nanotube thin film post-treatment process method,
Board;
A carbon nanotube conductive film formed on the substrate; And
It is formed using a post-treatment solution and a reaction initiation solution containing at least one titanium alkoxide (titanium alkoxide) on the conductive film and comprises a compound film containing a carbon nanotube and a titanium compound,
The titanium alkoxide is
A composition formed by the method of post-treatment of an electrically and thermally conductive carbon nanotube thin film, characterized in that for selecting a kind of precipitated as a titanium compound through decomposition, exchange, substitution, or condensation reaction in contact with the reaction starting solution. The method of claim 1, wherein the reaction starting solution
A composition formed by an electrical, thermally conductive carbon nanotube thin film post-treatment process comprising at least one of water, an acid, a base, an alcohol, a polymer solution having a -OH functional group, and a polymer solution having a -COOH functional group. delete In the composition formed by the electrically, thermally conductive carbon nanotube thin film post-treatment process method,
Board;
A carbon nanotube conductive film formed on the substrate;
A compound film formed using a post-treatment solution and a reaction initiation solution including at least one titanium alkoxide on the conductive film and including a carbon nanotube and a titanium compound; And
A composition formed by a post-treatment method of an electrically and thermally conductive carbon nanotube thin film, comprising a polymer film formed by coating a polymer material on the compound film. The method of claim 8,
The polymer material is a composition formed by a post-treatment method of an electrically, thermally conductive carbon nanotube thin film, characterized in that the material having a -COOH, -OH functional group. The method of claim 8,
The composite film formed by the post-treatment method of the electrical, thermally conductive carbon nanotube thin film, characterized in that it further comprises a composite film formed on the polymer film through the contact of the post-treatment solution and the reaction starting solution. The method of claim 1, wherein the substrate
A composition formed by an electrically thermally conductive carbon nanotube thin film post-treatment process using any one of glass, quartz, glass wafers, silicon wafers, transparent and opaque plastic substrates, and transparent and opaque polymer films. In the composition formed by the electrically, thermally conductive carbon nanotube thin film post-treatment process method,
Board;
A carbon nanotube conductive film formed on the substrate; And
It is formed using a post-treatment solution and a reaction initiation solution containing at least one titanium alkoxide (titanium alkoxide) on the conductive film and comprises a compound film containing a carbon nanotube and a titanium compound,
The conductive film is
At least one of single-walled carbon nanotubes, functionalized single-walled carbon nanotubes, double-walled carbon nanotubes, functionalized double-walled carbon nanotubes, multi-walled carbon nanotubes, and functionalized multi-walled carbon nanotubes is used. A composition formed by a thermally conductive carbon nanotube thin film post-treatment process method. In the thermally conductive carbon nanotube thin film post-treatment process method,
The process of preparing a substrate,
Forming a conductive film using a carbon nanotube dispersion solution on the substrate;
A process of forming a compound film including carbon nanotubes and a titanium compound to a thickness of greater than 0 and 50 nm or less using a post-treatment solution and a reaction initiation solution including at least one titanium alkoxide on the conductive film. Electrical, thermally conductive carbon nanotubes thin film post-treatment process method comprising a. The method of claim 13, wherein the titanium compound
An electrically conductive thermally conductive carbon nanotube thin film post-treatment process comprising titanium hydroxide and titanium oxide. The method of claim 13, wherein the titanium alkoxide is
Titanium (oxygen) -oxygen atom-organic substituent (R) structure, characterized in that the thermally conductive carbon nanotube thin film post-treatment process method. The method of claim 13, wherein the titanium alkoxide is
According to the form of the organic substituent (R), at least any one of titanium methoxide, titanium ethoxide, titanium propoxide, titanium isopropoxide, titanium butoxide, titanium pentoxide is selected. In the thermally conductive carbon nanotube thin film post-treatment process method,
The process of preparing a substrate,
Forming a conductive film using a carbon nanotube dispersion solution on the substrate;
Forming a compound film including carbon nanotubes and a titanium compound by using a post-treatment solution and a reaction initiation solution including at least one titanium alkoxide on the conductive film;
The titanium alkoxide is
Electrical and thermally conductive carbon nanotube thin film post-treatment process characterized in that the contact with the reaction initiation solution to select a kind of precipitated as a titanium compound through decomposition, exchange, substitution, or condensation reaction. The method of claim 13,
The concentration of the titanium alkoxide in the after-treatment solution is greater than 0 wt% 30 wt% or less, characterized in that the post-treatment process of the carbon nanotube thin film. The method of claim 13, wherein the solvent of the aftertreatment solution is
Electrothermal thermally conductive carbon nanotube thin film post-treatment process characterized in that the alcohol, such as methanol, ethanol, propanol, isopropanol, butanol and mixtures thereof. In the thermally conductive carbon nanotube thin film post-treatment process method,
The process of preparing a substrate,
Forming a conductive film using a carbon nanotube dispersion solution on the substrate;
Forming a compound film including carbon nanotubes and a titanium compound by using a post-treatment solution and a reaction initiation solution including at least one titanium alkoxide on the conductive film;
The reaction starting solution
An electrical, thermally conductive carbon nanotube thin film post-treatment process comprising at least one of water, an acid, a base, an alcohol, a polymer solution having a -OH functional group, and a polymer solution having a -COOH functional group. In the thermally conductive carbon nanotube thin film post-treatment process method,
The process of preparing a substrate,
Forming a conductive film using a carbon nanotube dispersion solution on the substrate;
Forming a compound film including carbon nanotubes and a titanium compound by using a post-treatment solution and a reaction initiation solution including at least one titanium alkoxide on the conductive film;
The process of forming the compound film
After the post-treatment solution is coated on the conductive film, before the post-treatment solution is dried, by contacting the reaction starting solution, the electrothermally conductive carbon nanotube thin film post-treatment process method. The method of claim 21, wherein the contact is
Any one of dip coating, spray coating, spin coating, solution casting, dropping, roll coating, gravure coating, bar coating Electrical, thermally conductive carbon nanotube thin film post-treatment process characterized in that carried out by the method. In the thermally conductive carbon nanotube thin film post-treatment process method,
The process of preparing a substrate,
Forming a conductive film using a carbon nanotube dispersion solution on the substrate;
Forming a compound film including carbon nanotubes and a titanium compound by using a post-treatment solution and a reaction initiation solution including at least one titanium alkoxide on the conductive film;
Post-treatment method of the electrically, thermally conductive carbon nanotube thin film comprising the step of forming a polymer film by coating a polymer material on the compound film. The method of claim 23, wherein
The polymer material is -COOH, -OH conductive, characterized in that the material having a functional group carbon nanotube thin film post-treatment process. The method of claim 23, wherein
The method of claim 1, further comprising forming a composite film by coating the post-treatment solution on the polymer membrane and contacting the reaction initiation solution. In the thermally conductive carbon nanotube thin film post-treatment process method,
The process of preparing a substrate,
Forming a conductive film using a carbon nanotube dispersion solution on the substrate;
Forming a compound film including carbon nanotubes and a titanium compound by using a post-treatment solution and a reaction initiation solution including at least one titanium alkoxide on the conductive film;
Before the process of forming the conductive film,
Piranha solution treatment, acid treatment, base treatment, plasma treatment, atmospheric pressure plasma treatment, ozone treatment, UV treatment, SAM (self assembled monolayer) treatment, and polymer or monomolecular coating method on the substrate The electrothermally conductive carbon nanotube thin film post-treatment process method further comprising the step of performing a surface treatment using. The process of claim 13, wherein the forming of the conductive film is performed.
Dip coating, spray coating, spin coating, solution casting, dropping, roll coating, gravure coating of the carbon nanotube dispersion solution on the substrate Electrothermal thermally conductive carbon nanotube thin film post-treatment process method characterized in that the coating by using any one of the methods.

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