JP2001011344A - Coating and film formed using the same and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating which can uniformly form a mono-layered nanotube-containing substance layer on a large area surface or a non-flat surface and whose cost can be lowered, by dispersing mono-layered nanotube in a solution containing an organic polymer material. SOLUTION: This coating is obtained by dispersing (B) mono-layered nanotube (preferably mono-layered carbon nanotube) in (A) a solution containing an organic polymer material (preferably polymethyl methacrylate). The solution contains the component A in an amount of 1 to 50 v/v% based on the solvent and the component B in an amount of 0.1 to 10 w/w%. The coating is preferably provided with a process for dispersing the component B in a solution containing the component A with ultrasonic waves, for example, under an ultrasonic wave treatment condition in an output power of 200 W for about 2 hr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint suitable for use in forming a material layer containing single-walled nanotubes on a substrate, a film formed using the same, and a method for producing the same. .

[0002]

2. Description of the Related Art Since the discovery of single-walled carbon nanotubes having nanometer-scale fine structures by Iijima et al.
The physical properties of the single-walled carbon nanotube are being elucidated, and research and development for its application are being actively conducted. This single-walled carbon nanotube is a tube formed by rolling a flat graphite hexagonal mesh into a tube. Since the electronic structure changes greatly depending on the tube diameter and the chiral angle, the electric conductivity has a value between a metal and a semiconductor. However, it is said to exhibit properties close to one-dimensional electric conduction.

In recent years, techniques for forming a material layer containing carbon nanotubes on a substrate have been proposed (for example, Sc.
issue, vol. 282, p. 1105, (199
8), Nature, vol. 283, p. 512,
(1999), etc.). This technique is based on a chemical vapor deposition (CVD) method.
By depositing carbon nanotubes on the substrate by an evaporation method), a material layer containing carbon nanotubes is formed on the surface of the substrate.

[0004]

However, in the technique using the CVD method, it is difficult to uniformly form a material layer containing carbon nanotubes on a large-area surface or a non-flat surface. was there. In addition, in this technique, since the process temperature, conditions, equipment, and the like are severely restricted, and the obtained material layer containing carbon nanotubes is expensive, it is necessary to form the material layer containing carbon nanotubes at low cost. The development of technology that can do this was desired.

The present invention has been made in view of the above circumstances, and it is possible to uniformly form a material layer containing single-walled nanotubes on a large-area surface or a non-flat surface.
Moreover, it is an object of the present invention to provide a paint that can be reduced in cost, a film formed using the paint, and a method for manufacturing the same.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides the following paints, films formed using the same, and methods for producing them. That is, claim 1
The paint described is characterized in that single-wall nanotubes are dispersed in a solution containing an organic polymer material.

According to a second aspect of the present invention, there is provided the coating material according to the first aspect, wherein the single-walled nanotube is a single-walled carbon nanotube.

[0008] The paint according to the third aspect is the first or second aspect.
The coating composition according to claim 1, wherein the solution contains 1 to 50 v / v% of the organic polymer material with respect to a solvent, and 0.1 to 10 w / w% of the single-walled nanotube with respect to the solution. Features.

According to a fourth aspect of the present invention, there is provided the paint according to the first, second or third aspect, wherein the organic polymer material is polymethyl methacrylate.

[0010] The film according to claim 5 is provided on a substrate.
A film formed using the paint described in 2, 3, or 4, wherein an end of the single-walled nanotube is exposed on a main surface of the film.

The method for producing a paint according to a sixth aspect is characterized in that the method comprises a step of dispersing the single-walled nanotubes in a solution containing an organic polymer material by using ultrasonic waves.

According to a seventh aspect of the present invention, there is provided a method of forming a film on a substrate by using the coating according to the first, second, third or fourth aspect, wherein the coating is formed by spraying. The method is characterized in that a step of coating the substrate is provided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION One embodiment of the paint of the present invention, a film formed using the paint and a method for producing the same will be described. This paint, in a solution containing an organic polymer material,
Single-walled nanotubes are uniformly dispersed.

As the single-walled nanotube, a single-walled carbon nanotube synthesized by the following method is preferably used. In order to synthesize this single-walled carbon nanotube, first, a carbon rod containing nickel (Ni) and cobalt (Co) in an amount of 0.3 atomic% is prepared as a target, and the target is placed in an electric furnace at, for example, 1200 ° C.
The target is irradiated with a pulse laser while being heated at a high temperature and flowing an inert gas such as argon (Ar). Thereby, a single-walled carbon nanotube can be obtained.

The single-walled carbon nanotube may be synthesized by another synthesis method such as an arc discharge method or a CVD method, in addition to the above synthesis method. As the solution, an organic polymer material such as polymethyl methacrylate (PMMA) is used in a solvent such as monochlorobenzene.
Using a solution containing 50 v / v%, single-walled carbon nanotubes are added in an amount of 0.1 to 10 w / w% to the solution.

By applying this coating material on a substrate by using a spray method, a uniform film without aggregation can be obtained. By using this spray method, the paint adheres to the substrate in the form of fine particles, and aggregation can be suppressed to a minimum. FIG. 1 is a scanning electron microscope image (SEM) showing a film formed on a substrate using the coating material of the present embodiment.
In the figure, white linear portions are single-walled carbon nanotubes, and black portions are polymethyl methacrylate (PMMA). According to FIG. 1, it is clear that single-walled carbon nanotubes are dispersed in polymethyl methacrylate (PMMA).

Next, a method for producing the paint of the present embodiment will be described. First, a nanotube is synthesized, and the obtained nanotube is added to a polymethyl methacrylate solution and stirred. Here, using the single-walled carbon nanotube synthesized by the above-described synthesis method, the obtained single-walled carbon nanotube was added to the polymethyl methacrylate solution and stirred.

More specifically, 60 mg of single-walled carbon nanotubes is added to 10 ml of polymethyl methacrylate solution.
added. As a solvent for the polymethyl methacrylate solution, for example, monochlorobenzene is suitable. Since monochlorobenzene has the property of dissolving carbon impurities generated during nanotube formation, it works effectively as a solvent for paints.

Here, the concentration of polymethyl methacrylate was 1%. The ratio of polymethyl methacrylate may be increased up to 50% in consideration of an increase in viscosity or a decrease in the density of nanotubes after film formation. In this stirring step, it is effective to perform ultrasonic treatment in order to uniformly disperse the nanotubes in the solution. By using this ultrasonic treatment, the entangled nanotubes are unraveled, and carbon impurities generated at the time of nanotube formation are dissolved in the solvent and separated.

There are no particular restrictions on the conditions of the ultrasonic treatment, but it is sufficient that the ultrasonic intensity and the treatment time are sufficient to uniformly disperse the nanotubes in the solution. As an example of the condition of the ultrasonic treatment, a processing time of 2 hours at an output voltage of 200 W can be cited.

According to the paint of the present embodiment, the adhesion to the substrate such as the substrate is excellent, and the material layer containing the single-walled nanotubes can be uniformly applied to a large-area surface or a non-flat surface. And cost reduction can be achieved. According to the film of the present embodiment, it is possible to form a uniform material layer containing single-walled nanotubes on a substrate such as a substrate.

According to the method for producing a coating material of the present embodiment, single-walled nanotubes can be uniformly dispersed in a solution containing an organic polymer material, and a highly uniform coating material can be produced. According to the film manufacturing method of the present embodiment, since the coating material is applied to the substrate by using the spray method, the coating material can be minimized in aggregation by adhering to the substrate in the form of fine particles, A uniform film without aggregation can be obtained.

As mentioned above, one embodiment of the paint of the present invention, a film formed by using the paint and a method for producing the same has been described with reference to the drawings. However, the specific structure is not limited to this embodiment. The design can be changed without departing from the spirit of the present invention. For example, in the above embodiment, monochlorobenzene was used as the solvent, and polymethyl methacrylate (PMMA) was used as the organic polymer material. However, the solvent and the organic polymer material are used to uniformly disperse single-walled nanotubes, What is necessary is just to be the thing excellent in the adhesiveness with respect to a base material, and it is not limited to said material.

[0024]

As described above, according to the coating material of the present invention, single-wall nanotubes are dispersed in a solution containing an organic polymer material. , Can prevent aggregation,
Adhesion to a substrate such as a substrate can be improved. Therefore, even for large area surfaces and non-flat surfaces,
A material layer containing single-walled nanotubes can be formed uniformly, and the cost can be reduced.

According to the film of the present invention, since the end portion of the single-walled nanotube is exposed on the main surface of the film, the material layer containing the uniformed single-walled nanotube is formed on a substrate such as a substrate. Can be formed.

According to the method for producing a coating material of the present invention, a step of dispersing single-walled nanotubes in a solution containing an organic polymer material by using ultrasonic waves is provided. In addition, the single-walled nanotubes can be uniformly dispersed, and a highly uniform coating material can be manufactured.

According to the method for producing a film of the present invention, the step of applying the coating material on the substrate by a spray method is provided, so that the coating material adheres to the substrate in the form of fine particles to minimize aggregation. Thus, a uniform film without aggregation can be obtained.

[Brief description of the drawings]

FIG. 1 is a scanning electron microscopic image showing a film formed on a substrate using a coating material according to an embodiment of the present invention.

Claims (7)

[Claims] 1. A paint comprising a single-walled nanotube dispersed in a solution containing an organic polymer material. 2. The coating according to claim 1, wherein the single-walled nanotube is a single-walled carbon nanotube. 3. The solution according to claim 1, wherein the organic polymer material is contained in an amount of 1 to 50 v / v% with respect to a solvent, and the single-walled nanotube is contained in an amount of 0.1 to 10 w / w% with respect to the solution. The paint according to claim 1 or 2, wherein 4. The method according to claim 1, wherein the organic polymer material is polymethyl methacrylate.
The paint described. 5. A film formed on a substrate using the paint according to claim 1, 2, 3 or 4, wherein an end portion of the single-walled nanotube is exposed on a main surface of the film. A film characterized by the above. 6. A method for producing a paint, comprising a step of dispersing single-walled nanotubes in a solution containing an organic polymer material using ultrasonic waves. 7. A method for producing a film by using the paint according to claim 1, 2, 3 or 4 on a substrate, comprising a step of applying the paint on the substrate by a spray method. A method for producing a film.