WO2012086174A1

WO2012086174A1 - Carbon-nanotube-dispersed paste, method for producing same, circuit board, emitter electrode, and field-emission light-emitting element

Info

Publication number: WO2012086174A1
Application number: PCT/JP2011/007085
Authority: WO
Inventors: 眞由美小坂
Original assignee: 日本電気株式会社
Priority date: 2010-12-20
Filing date: 2011-12-19
Publication date: 2012-06-28
Also published as: JP5861646B2; JPWO2012086174A1

Abstract

Provided is a carbon-nanotube-dispersed paste wherein carbon nanotubes are evenly dispersed in a solvent that does not impart a negative effect on the components other materials. The carbon-nanotube-dispersed paste has: a solvent (A) that is at least 90 vol% and less than 99.9999 vol% of the entire solvent and that has a boiling point of at least 150°C; and a solvent (B) that has a vol% that is no greater than the remnant from solvent (A) and that has a lower boiling point than solvent (A). In order to disperse carbon nanotubes, for example, a plurality of types of ultrasonic wave having differing frequencies, strengths, or application conditions are radiated at solvent (B), and by means of replacement with solvent (A), carbon nanotubes, which have poor dispersibility, can be highly efficiently dispersed in a solvent in a short period of time.

Description

Carbon nanotube dispersion paste, manufacturing method thereof, circuit board, emitter electrode, field emission light emitting device

The present invention relates to a carbon nanotube-dispersed paste in which carbon nanotubes are dispersed in a solvent, a manufacturing method thereof, a circuit board, an emitter electrode, and a field emission light-emitting device.

As a method for forming a circuit pattern on a circuit board, in recent years, a method for forming a circuit pattern on a circuit board by printing using a conductive paste has been developed. In particular, when a circuit pattern is formed on a conductive material for electronic components having low heat resistance or a substrate material having low heat resistance, a conductive paste that cures in a relatively low temperature range, for example, a temperature range of 180 ° C. or less, is required. It has been.

導電 Conductive paste is used for electrical connection of electronic parts and circuit pattern formation, so it must have low resistance. However, the low temperature curing type conductive paste has a small volume shrinkage rate when cured, and it is difficult to stably secure a contact area between metal particles in the conductive paste.

For this reason, the low resistance necessary for practical use could not be obtained. Therefore, it has been proposed to mix carbon nanotubes with the conductive paste (Patent Documents 1 to 3).

Carbon materials such as carbon nanotubes and carbon nanofibers are widely used as electron emission sources for field emission displays (FED), liquid crystal backlights using field emission, field emission illumination (FEL), and the like.

In particular, carbon nanotubes (CNT) not only have excellent chemical and mechanical durability, but also have a sharp tip shape and large aspect ratio suitable for field emission, and are actively researched as an excellent electron emission source. Has been.

In order to produce a field emission electrode, first, a carbon material as an electron emission source, an inorganic material such as glass powder for bonding the carbon material and the cathode electrode, an organic binder as an electrode structure support member, and an organic binder are dissolved. The paste to be used for the field emission electrode is prepared by mixing the solvent to be used.

JP 2008-293821A JP 2006-120665 A JP 2009-117340 A

Since carbon nanotubes have a high aspect ratio, the carbon nanotubes are bundled or entangled. As a result, the dispersion characteristics with respect to the solvent and other materials are poor, and it is difficult to uniformly disperse in the conductive paste, so it is not easy to ensure high conductivity.

Especially, carbon nanotubes with high conductivity have few defects, and the graphite layer constituting the carbon nanotubes has an ordered six-membered ring arrangement structure, so that it is difficult to be cut when dispersed in the conductive paste. Further, since there are few functional groups on the surface, dispersion is difficult.

Highly conductive carbon nanotubes have a low D / G ratio measured by Raman spectroscopy. The D / G ratio is an intensity ratio between a G band which is a Raman band unique to a nanotube and a D band derived from a defect. Here, for example, carbon nanotubes having a D / G ratio of 0.2 or less are difficult to disperse.

Further, the density of the carbon nanotube is about several tens mg / cm ³ , and when the carbon nanotube is dispersed in a high boiling point solvent used for the conductive paste, the density of the solvent is about 50 to 100 times. The volume of the solvent is very small relative to the volume of. For this reason, it is difficult to disperse the carbon nanotubes.

When carbon nanotubes are dispersed in other materials such as conductive paste using a dispersion solution in which carbon nanotubes are dispersed in a solvent other than the solvent used for the conductive paste, there are other solvents for dispersing the carbon nanotubes. It may have an adverse effect of decomposing or modifying a resin or a curing agent that is a component of the material. For example, when a carbon nanotube dispersion solution dispersed with a solvent that decomposes the resin of the conductive paste is directly mixed with the conductive paste material, the characteristics of the conductive paste are lowered and the resistance is increased.

Also in the field emission source electrode paste, in the conventional method, the carbon nanotubes serving as the electron emission source are not uniformly mixed, but are aggregated and entangled in a bundle shape or a dumpling shape.

When carbon nanotubes are agglomerated, it becomes difficult to uniformly knead with glass powder or organic binder. As a result, the number of electron emission sources is reduced when electrons are emitted from the manufactured electrode, so that electrons are not emitted uniformly.

In particular, carbon nanotubes having good crystallinity are considered good because they have high electron emission characteristics, but it is difficult to produce a uniform kneaded paste because they are difficult to disperse. As a result, the number of bright spots of the field emission device is greatly reduced.

The present invention has been made in view of the above problems, and provides a carbon nanotube dispersion paste in which carbon nanotubes are uniformly dispersed in a solvent that does not adversely affect the components of other materials, and a method for producing the same. Is.

According to the present invention, the carbon nanotubes are dispersed in a solvent,
A solvent (A) having a boiling point of not less than 90% by volume and less than 99.9999% by volume and having a boiling point of not less than 150 ° C. in all the solvents;
A solvent (B) having a boiling point lower than that of the solvent (A) in the remaining volume% or less of the solvent (A);
A carbon nanotube dispersion paste is provided.

The reason why the boiling point of the solvent (A) is 150 ° C. or more is that when the carbon nanotube-dispersed paste is stored at room temperature, the solvent (A) does not volatilize for a long time and the paste concentration does not change. . In addition, it is preferable that the boiling point of a solvent (B) is 10 degreeC or more lower than the boiling point of a solvent (A).

In the carbon nanotube dispersion paste of the present invention, it is desirable that 1 part by weight of the carbon nanotubes are dispersed in 1 to 100 parts by weight of the solvent. When the density of the carbon nanotube is about 20 mg / cm ³ , the density of the solvent is about 50 times that. Therefore, in the state where 1 part by weight of the carbon nanotubes are dispersed in 1 to 100 parts by weight of the solvent, the volume ratio of the solvent is about 0.02 to 2 times the volume of the carbon nanotubes. It becomes. When the amount of the solvent with respect to the carbon nanotube is increased to 101 parts by weight or more, the viscosity of the carbon nanotube-dispersed paste decreases as the amount of the solvent increases, and becomes a solution.

The carbon nanotube dispersion paste of the present invention may further contain conductive particles and a binder.

In addition, according to the present invention, there is provided a circuit board in which a circuit pattern is formed on a substrate using a conductive paste containing the carbon nanotube dispersion paste.
Furthermore, according to the present invention, there is provided an emitter electrode using the carbon nanotube dispersion paste as an electron emission source.
Furthermore, according to the present invention, there is provided a field emission light-emitting device comprising the emitter electrode and a phosphor layer provided opposite to the emitter electrode and emitting light when electrons emitted from the emitter collide with each other. Is done.

Furthermore, according to the present invention, the step of dispersing the carbon nanotubes in a solvent (B) having a boiling point of 150 ° C. or higher and a solvent (B) to produce a carbon nanotube dispersion solution;
Replacing the carbon nanotube dispersion solution with the solvent (A) to obtain a carbon nanotube dispersion paste;
A method for producing a carbon nanotube-dispersed paste having the following is provided.

Further, in the step of generating the carbon nanotube dispersion solution, ultrasonic waves may be irradiated to disperse the carbon nanotubes in the solvent (B), and at least one of frequency and intensity is different. The ultrasonic waves may be alternately applied.

Furthermore, in the step of obtaining the carbon nanotube dispersion paste, the solvent (B) may be volatilized by mixing and kneading. In addition, after the step of obtaining the carbon nanotube dispersion paste, the step of simultaneously mixing and kneading the carbon nanotube dispersion paste, the conductive particles, and the binder, or the first mixing and kneading step of mixing and kneading the conductive particles and the binder, A second mixing and kneading step of adding and mixing and kneading the carbon nanotube dispersion paste after the first mixing and kneading step; and a step of curing the carbon nanotube dispersion paste at a temperature not higher than the boiling point of the solvent (A); , May further be included.

The various components of the present invention do not necessarily have to be independent of each other. A plurality of components are formed as a single member, and a single component is formed of a plurality of members. It may be that a certain component is a part of another component, a part of a certain component overlaps with a part of another component, or the like.

Moreover, although the manufacturing method of the present invention describes a plurality of manufacturing steps in order, the order of description does not limit the order of executing the plurality of manufacturing steps. For this reason, when implementing the manufacturing method of this invention, the order of the some manufacturing process can be changed in the range which does not interfere in content.

Furthermore, the manufacturing method of the present invention is not limited to the case where a plurality of manufacturing processes are executed at different timings. For this reason, another manufacturing process may occur during the execution of a certain manufacturing process, or a part or all of the execution timing of a certain manufacturing process and the execution timing of another manufacturing process may overlap.

The carbon nanotube-dispersed paste of the present invention is 90% by volume or more and less than 99.9999% by volume in the total solvent, the solvent (A) having a boiling point of 150 ° C. or more, and the remaining volume% or less of the solvent (A), and And a solvent (B) having a lower boiling point than that of the solvent (A). By using the solvents (A) and (B) having different boiling points in this way, it is possible to realize a carbon nanotube dispersion paste in which carbon nanotubes are uniformly dispersed in a solvent that does not adversely affect the components of other materials. .

The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.

It is a schematic diagram of the electrically conductive paste in 1st embodiment of this invention. It is process drawing at the time of supplying electrically conductive paste to the surface of a circuit board in a second embodiment. It is a perspective view which shows typically an example of a structure of the cathode electrode of FED and FEL in 4th embodiment. It is a figure showing the light emission photograph of the field emission electrode of Example 7 in 4th embodiment. It is a figure showing the light emission photograph of the field emission electrode of the comparative example 7 in 4th embodiment.

[First embodiment]
Below, the preferable form for implementing this invention is demonstrated. However, technically preferable limitations for carrying out the present invention are provided in the embodiments described below, but the scope of the invention is not limited to the following.

The carbon nanotube-dispersed paste 1 of the present embodiment includes a solvent (A) in which carbon nanotubes are dispersed in a solvent, 90% by volume to less than 99.9999% by volume, and a boiling point of 150 ° C. or higher in the total solvent, A solvent (B) having a boiling point lower than that of the solvent (A) in the remaining volume% or less of (A).

Examples of the solvent (A) having a boiling point of 150 ° C. or higher include 2-ethoxyethyl acetate, 2-n-butoxyethanol, dimethyl sulfoxide, 2-n-butoxyethyl acetate, ethyl carbitol, carbitol acetate, terpineol, Examples thereof include butyl carbitol and butyl carbitol acetate.

Examples of the solvent (B) having a boiling point lower than that of the solvent (A) include solvents having a boiling point of 150 ° C. or less, such as acetone, tetrahydrofuran, hexane, ethanol, acetonitrile, isopropyl alcohol, 1,2-dichloroethane, toluene, diethoxyethane. It is done. The solvent (B) may be any of these solvents, or a solvent having a boiling point of 150 ° C. or higher as long as the boiling point is lower than that of the solvent (A) to be used. In addition, it is preferable that a solvent (B) is a solvent which has a boiling point 10 degreeC or more lower than a solvent (A). In the present embodiment, by using solvents (A) and (B) having different boiling points, carbon nanotubes having poor dispersibility are dispersed with high efficiency using ultrasonic waves in a large amount of solvent (B). By substituting with the solvent (A), the carbon nanotube dispersed paste 1 well dispersed in a small amount of the solvent (A) can be obtained.

Hereinafter, a method for producing a carbon nanotube-dispersed paste according to this embodiment will be described.

The carbon nanotube dispersion paste 1 is manufactured by the method described below, for example.
First, the carbon nanotubes 2 are dispersed in the solvent (B), and a plurality of types of ultrasonic waves having different frequencies and intensities or a plurality of types of ultrasonic waves having different application conditions are irradiated in combination. Here, the ultrasonic waves with different application conditions indicate, for example, chip-type ultrasonic waves, probe-type ultrasonic waves, bus-type ultrasonic waves, or the like. Thus, by irradiating with ultrasonic waves, the carbon nanotubes 2 with poor dispersibility in the solvent can be dispersed efficiently in a short time, and a carbon nanotube dispersion solution can be obtained.

Next, the solvent (B) in the carbon nanotube dispersion solution is replaced with a small amount of the solvent (A). Here, the small amount means an amount of 1 to 100 parts by weight of the solvent with respect to 1 part by weight of the carbon nanotube. As the replacement method, a three-roll mill, a homogenizer, a slip pulverizer, or the like that can replace the solvent (B) with the solvent (A) while kneading is used. By kneading using these tools, the carbon nanotubes dispersed in the solvent (B) are maintained, and even in the solvent (A), the carbon nanotubes are appropriately cut and dispersed without deteriorating the carbon nanotubes. Can raise the sex. By doing so, a highly dispersed carbon nanotube dispersion paste 1 can be produced.

The carbon nanotube 2 used in the present embodiment includes a single-walled carbon nanotube, a double-walled carbon nanotube, a multi-walled carbon nanotube, a carbon nanohorn, a carbon nanohorn aggregate, and a carbon nanotube having a structure in which at least one of the carbon nanotube and the carbon nanohorn is joined. Includes carbon nanostructures, such as nanohorn composites.

Among these carbon nanostructures, in particular, the carbon nanotubes 2 having a good crystallinity with a D / G ratio of 0.2 or less measured by Raman spectroscopic analysis have high conductivity.

However, carbon nanotubes having a D / G ratio of 0.2 or less have poor dispersibility. For this reason, by using the manufacturing method of this embodiment, the effect of improving dispersibility is high. On the other hand, when the D / G ratio of carbon nanohorn or the like is larger than 0.2, the effect of improving the dispersibility by the manufacturing method of the present embodiment is smaller than that when the D / G ratio is 0.2 or less. Larger than the method of.

In the carbon nanotube dispersion paste 1 produced by the above method, a slight amount of solvent (B) remains upon solvent substitution. For this reason, the solvent (A) having a boiling point of 150 ° C. or higher is 90% by volume or more and less than 99.9999% by volume in the total solvent, and the solvent (B) having a boiling point lower than that of the solvent (A) is 0.0001 in the total solvent. Containing at least 10% by volume.

A conductive paste is prepared by adding conductive particles, a curable resin as a binder, and a curing agent to the carbon nanotube dispersion paste 1 prepared as described above.

FIG. 1 is a schematic view of a conductive paste in the first embodiment of the present invention.
As shown in FIG. 1, in the conductive paste, carbon nanotubes 2, conductive particles 3, and curable resin 4 are uniformly mixed. As described above, the carbon nanotubes 2, the conductive particles 3, and the curable resin 4 are uniformly mixed as compared with the case where the carbon nanotubes 2 are mixed between the conductive particles 3. However, it is possible to form an electrical bridge and to improve the conductivity of the conductive paste.

The conductive particles 3 are composed of one kind selected from the group consisting of silver, copper, gold, tin, indium, nickel and palladium, or a mixture of a plurality of kinds of particles or an alloy. The shape of the conductive particles 3 is not particularly limited, and various shapes such as spherical, scale-like, plate-like, dendritic, massive, granular, rod-like, foil-like, and needle-like particles are used. be able to.

As the curable resin 4, a resin such as a thermosetting resin or a photocurable resin can be used in the presence of a suitable combination of curing agents. Examples of such resins include one or more selected from the group consisting of epoxy resins, acrylic resins, phenol resins, polyimide resins, silicone resins, polyurethane resins, and unsaturated polyester resins. Can be used.

The above-mentioned curing agent is generally known as a combination of suitable curing agent components corresponding to the curable resin 4, and such a combination can also be used in this embodiment. For example, when an epoxy resin is used as the curable resin 4, a substance selected from thiol, amine, and acid anhydride can be used as the curing agent component.

The carbon nanotube dispersion paste 1 of the present embodiment can uniformly disperse the carbon nanotubes 2 in the solvent of the conductive paste or the solvent (A) having a similar structure. For this reason, when mixing and kneading with the conductive particles 3, the curable resin 4, and the curing agent, the influence of the solvent component that disperses the carbon nanotubes 2 decomposes or denatures the material of the conductive paste is minimized. be able to.

Thus, the carbon nanotube dispersion paste 1 is mixed and kneaded with the conductive particles 3, the curable resin 4, and a curing agent (not shown), whereby the carbon nanotubes 2 are uniformly dispersed between the conductive particles 3. Sex paste can be obtained.

The method of preparing the conductive paste by kneading the carbon nanotube dispersion paste 1 with the conductive particles 3, the curable resin 4, and the curing agent is to mix and knead the carbon nanotube dispersion paste simultaneously with other conductive paste materials. The conductive paste may be prepared, or the conductive paste may be prepared by adding the carbon nanotube dispersion paste 1 to the conductive paste having already been kneaded with other materials and kneading. Even if either of the above-described production methods is used, a conductive paste in which carbon nanotubes are uniformly dispersed can be produced.

When the curable resin 4 is cured, the conductive paste shrinks the entire volume of the curable resin 4, so that the interval between the conductive particles 3 is narrowed. As a result, the carbon nanotubes 2 between the conductive particles 3 can serve as a good conductive path for the conductive particles 3.

On the other hand, when the carbon nanotubes 2 are not uniformly dispersed in the conductive resin, there may be a place where the carbon nanotubes 2 are not between the conductive particles 3, or the carbon nanotubes 2 are conductive at the aggregated portion. It may occur that the distance between the particles 3 increases and the conductivity is hindered.

The conductive paste using the carbon nanotube dispersion paste 1 according to the present embodiment can form the conductive connection of the conductive particles 3 by uniformly dispersing the carbon nanotubes 2 between the conductive particles 3. For this reason, compared with the conventional electrically conductive paste, the electrically conductive paste which concerns on this embodiment can implement | achieve high electroconductivity.

Examples and comparative examples are shown below, and the present embodiment will be described more specifically. However, the invention is not limited by the following examples.
In the following examples and comparative examples, each step of preparing a sample (step 1A, step 1A ′, step 1B, step 2) means an embodiment shown below.
Step 1A: Irradiation of ultrasonic waves with carbon nanotubes and solvent (B) under two conditions Step 1A ': Irradiation of ultrasonic waves with carbon nanotubes and solvent (A) under two conditions Step 1B: Carbon nanotubes And solvent (B) are irradiated with ultrasonic waves under one condition Step 2: The solvent (B) in the carbon nanotube dispersion solution is replaced with the solvent (A) to obtain a carbon nanotube dispersion paste

[Example 1]
Mixing 1 part by weight of carbon nanotubes with 1000 parts by weight of isopropanol (boiling point 82 ° C.), and alternately irradiating 45 kHz, 100 W bath type ultrasonic waves and 20 kHz, 300 W probe type ultrasonic waves, Produced (step 1A).

The carbon nanotube dispersion solution thus prepared and 10 parts by weight of butyl carbitol acetate (BCA; boiling point 247 ° C.) were mixed, and while kneading using a three-roll mill, the solvent was replaced by volatilizing isopropanol. A BCA dispersion paste was prepared (step 2). The solvent component in the dispersion paste was about 1% by volume of isopropanol and 99% by volume of BCA.

The carbon nanotube / BCA dispersion paste thus prepared is mixed and kneaded with conductive particles and the like by a three roll mill, and 1 part by weight of carbon nanotubes, 200 parts by weight of silver particles, 20 parts by weight of epoxy resin, and 2 parts by weight of a curing agent. The electroconductive paste comprised by these was manufactured (in Table 1, <mixture of materials>). After the conductive paste was cured at 150 ° C., the specific resistance was measured. The results are shown in Table 1.

[Example 2]
A carbon nanotube dispersion solution was prepared by mixing 1 part by weight of carbon nanotubes with 1000 parts by weight of isopropanol and irradiating bath-type ultrasonic waves of 45 kHz and 100 W (step 1B).

The carbon nanotube dispersion solution thus prepared and 10 parts by weight of BCA were mixed, and while kneading using a three roll mill, isopropanol was volatilized and solvent substitution was performed to prepare a BCA dispersion paste of carbon nanotubes (step 2).

The carbon nanotube / BCA dispersion paste thus prepared is mixed and kneaded with conductive particles and the like by a three roll mill, and 1 part by weight of carbon nanotubes, 200 parts by weight of silver particles, 20 parts by weight of epoxy resin, and 2 parts by weight of a curing agent. The conductive paste comprised by these was manufactured. After the conductive paste was cured at 150 ° C., the specific resistance was measured. The results are shown in Table 1. As a comparison with Example 1, Example 2 differs in that only one type of ultrasonic irradiation to the solvent (B) is used (Step 1B). That is, unlike the first embodiment, two types of ultrasonic waves are not used, but the process 2 is the same.

Example 3
A carbon nanotube dispersion solution was prepared by mixing 1 part by weight of carbon nanotubes with 1000 parts by weight of isopropanol and alternately irradiating 45 kHz, 100 W bath type ultrasonic waves and 20 kHz, 300 W probe type ultrasonic waves (step 1A). ).

After the carbon nanotube / BCA dispersion paste thus prepared was added to a silver paste in which 200 parts by weight of silver particles, 20 parts by weight of an epoxy resin, and 2 parts by weight of a curing agent were previously kneaded by a three-roll mill, And kneaded in a three-roll mill to produce a conductive paste (in Table 1, <after mixing>). After the conductive paste was cured at 150 ° C., the specific resistance was measured. The results are shown in Table 1.

[Comparative Example 1]
A conductive paste composed of 200 parts by weight of silver particles, 20 parts by weight of epoxy resin, and 2 parts by weight of a curing agent is manufactured by mixing and kneading with a three-roll mill, and cured at 150 ° C. It was measured. The results are shown in Table 1. As a comparison with Example 1, Comparative Example 1 does not use carbon nanotubes.

[Comparative Example 2]
A conductive paste composed of 1 part by weight of carbon nanotubes, 10 parts by weight of BCA solvent, 200 parts by weight of silver particles, 20 parts by weight of epoxy resin, and 2 parts by weight of a curing agent is produced by mixing and kneading with a three-roll mill. After being cured at 150 ° C., the specific resistance was measured. The results are shown in Table 1. As a comparison with Example 1, Comparative Example 2 has the same component ratio in the conductive paste, but does not use the carbon nanotube-dispersed paste of the present embodiment and the manufacturing method thereof.

[Comparative Example 3]
Carbon nanotube dispersion paste was prepared by mixing 1 part by weight of carbon nanotubes with 10 parts by weight of BCA and alternately irradiating 45 kHz, 100 W bath-type ultrasonic waves and 20 kHz, 300 W probe type ultrasonic waves (step 1A ′ ).

The carbon nanotube / BCA dispersion paste thus prepared is mixed and kneaded with conductive particles and the like by a three roll mill, and 1 part by weight of carbon nanotubes, 200 parts by weight of silver particles, 20 parts by weight of epoxy resin, and 2 parts by weight of a curing agent. The conductive paste comprised by these was manufactured. After the conductive paste was cured at 150 ° C., the specific resistance was measured. The results are shown in Table 1. As a comparison with Example 1, Comparative Example 3 is different in that only the solvent (A) is used and the above-described solvent replacement step (Step 2) is not used.

[Results of Examination of Example and Comparative Example According to First Embodiment]
As shown in Table 1, the conductive paste of Example 1 has a greater effect of reducing the specific resistance than the conductive pastes of Comparative Example 1 and Comparative Example 2. In other words, before the carbon nanotubes are mixed and kneaded with the conductive paste, when the carbon nanotube dispersed paste is uniformly dispersed in the solvent (A), the conductive paste is not mixed or mixed at the same time with the conductive paste. Compared with the case where kneading is performed, the specific resistance can be reduced and high conductivity can be realized.

Further, from the results of Table 1, since the conductive paste of Comparative Example 3 used only a small amount of solvent (A), there is an effect of improving dispersibility and reducing specific resistance by irradiating two types of ultrasonic waves. Since the dispersion of the carbon nanotubes is not uniform, the effect of reducing the specific resistance is smaller than that of the first embodiment.

The conductive paste of Example 2 was produced under the same conditions except that the two types of ultrasonic waves of Example 1 were replaced with one type of ultrasonic wave, and the carbon nanotubes were well dispersed to some extent. For this reason, the effect of reducing specific resistance is great.

The conductive paste of Example 3 was produced under the same conditions as in Example 1 except that a nanotube-dispersed paste was produced under the same conditions as in Example 1 and kneaded afterwards into a silver paste that had been previously kneaded. Since the carbon nanotubes are uniformly dispersed in the same manner as in Example 1, the specific resistance can be reduced.

[Second Embodiment]
Next, the second embodiment will be described in detail.
[Application to carbon nanohorn]
In the present embodiment, a dispersion paste and a conductive paste are produced using carbon nanohorns.

Hereinafter, examples and comparative examples will be shown, and this embodiment will be described more specifically. However, the invention is not limited by the following examples.

Example 4
By mixing 1 part by weight of carbon nanohorn with 1000 parts by weight of 1,2-dichloroethane (boiling point 84 ° C.), and alternately irradiating 45 kHz, 100 W bath type ultrasonic waves and 20 kHz, 300 W probe type ultrasonic waves, carbon A nanohorn dispersion was prepared (Step 1A).

The carbon nanohorn dispersion solution thus prepared and 10 parts by weight of BCA were mixed, and while kneading using a three-roll mill, 1,2-dichloroethane was volatilized and solvent substitution was performed to prepare a carbon nanohorn BCA dispersion paste ( Step 2).

The carbon nanohorn / BCA dispersion paste thus prepared is mixed and kneaded with conductive particles and the like by a three roll mill, 1 part by weight of carbon nanohorn, 190 parts by weight of silver particles, 10 parts by weight of epoxy resin, and 1 part by weight of a curing agent. The conductive paste comprised by these was manufactured. After the conductive paste was cured at 150 ° C., the specific resistance was measured. The results are shown in Table 2.

Example 5
A carbon nanohorn dispersion was prepared by mixing 1 part by weight of carbon nanohorn with 1000 parts by weight of 1,2-dichloroethane and irradiating bath-type ultrasonic waves of 45 kHz and 100 W (step 1B).

The carbon nanohorn / BCA dispersion paste thus prepared is mixed and kneaded with conductive particles and the like by a three roll mill, 1 part by weight of carbon nanohorn, 190 parts by weight of silver particles, 10 parts by weight of epoxy resin, and 1 part by weight of a curing agent. The conductive paste comprised by these was manufactured. After the conductive paste was cured at 150 ° C., the specific resistance was measured. The results are shown in Table 2. As a comparison with Example 4, Example 5 differs in that only one type of ultrasonic irradiation to the solvent (B) is used (Step 1B). That is, unlike the first embodiment, two types of ultrasonic waves are not used, but the process 2 is the same.

Example 6
A carbon nanohorn dispersion was prepared by mixing 1 part by weight of carbon nanohorn with 1000 parts by weight of 1,2-dichloroethane and irradiating bath-type ultrasonic waves of 45 kHz and 100 W (step 1B).

After the carbon nanohorn / BCA dispersion paste thus prepared was added to a silver paste in which 190 parts by weight of silver particles, 10 parts by weight of an epoxy resin, and 1 part by weight of a curing agent were previously kneaded by a three-roll mill, And kneaded with a three-roll mill to produce a conductive paste. After the conductive paste was cured at 150 ° C., the specific resistance was measured. The results are shown in Table 2.

[Comparative Example 4]
A conductive paste composed of 190 parts by weight of silver particles, 10 parts by weight of a BCA solvent, 10 parts by weight of an epoxy resin, and 1 part by weight of a curing agent is manufactured by mixing and kneading with a three-roll mill, and cured at 150 ° C. Thereafter, the specific resistance was measured. The results are shown in Table 2. As a comparison with Example 4, Comparative Example 4 does not use carbon nanohorns.

[Comparative Example 5]
A conductive paste composed of 1 part by weight of carbon nanohorn, 10 parts by weight of BCA solvent, 190 parts by weight of silver particles, 10 parts by weight of epoxy resin, and 1 part by weight of a curing agent is produced by mixing and kneading with a three-roll mill. After being cured at 150 ° C., the specific resistance was measured. The results are shown in Table 2. As a comparison with Example 4, Comparative Example 5 has the same component ratio in the conductive paste, but does not use the carbon nanohorn dispersion paste of this embodiment and the manufacturing method thereof.

[Comparative Example 6]
Carbon nanohorn dispersion paste was prepared by mixing 1 part by weight of carbon nanohorn with 10 parts by weight of BCA and alternately irradiating 45 kHz, 100 W bath type ultrasonic waves and 20 kHz, 300 W probe type ultrasonic waves (step 1A ′ ).

The carbon nanohorn / BCA dispersion paste thus prepared is mixed and kneaded with conductive particles and the like by a three roll mill, 1 part by weight of carbon nanohorn, 190 parts by weight of silver particles, 10 parts by weight of epoxy resin, and 1 part by weight of a curing agent. The conductive paste comprised by these was manufactured. After the conductive paste was cured at 150 ° C., the specific resistance was measured. The results are shown in Table 2. As a comparison with Example 4, Comparative Example 6 uses only the solvent (A) and does not use the above-described solvent replacement step (Step 2).

[Results of examination of the example and the comparative example according to the second embodiment]
As shown in Table 2, the conductive pastes of Examples 4, 5 and 6 have a greater effect of reducing the specific resistance than the conductive pastes of Comparative Example 4 and Comparative Example 5. That is, before carbon nanohorn is mixed and kneaded with conductive paste, when carbon nanohorn dispersed paste uniformly dispersed in solvent (A) is used, when conductive paste is not mixed or mixed with conductive paste, Compared with the case where kneading is performed, the specific resistance can be reduced and high conductivity can be realized.

Further, from the results of Table 2, since the conductive paste of Comparative Example 6 used only a small amount of solvent (A), there is an effect of improving dispersibility and reducing specific resistance by irradiating two types of ultrasonic waves. Dispersion is not uniform. For this reason, the effect of reducing the specific resistance is smaller than those of Examples 4-6.

The conductive paste of Example 5 was produced under the same conditions except that the two types of ultrasonic waves of Example 4 were replaced with one type of ultrasonic wave, and carbon nanohorns are more dispersible than carbon nanotubes. For this reason, even if one kind of ultrasonic treatment is performed, it is dispersed to some extent, and the effect of reducing specific resistance is great.

The conductive paste of Example 6 was prepared under the same conditions as in Example 5 except that a carbon nanohorn dispersion paste was prepared under the same conditions as in Example 5 and the silver paste was previously kneaded. . Since carbon nanohorns are uniformly dispersed in the same manner as in Example 5, the specific resistance can be reduced.

[Third embodiment]
Next, the third embodiment will be described in detail.
[Application to circuit boards]
In this embodiment, the conductive paste made of the carbon nanotubes, conductive particles, and curable resin produced in the first embodiment is used to form a circuit pattern on a substrate and mount an electronic component on the substrate. It is a case where it is used for.

As shown in the first embodiment, the conductive paste is prepared using a carbon nanotube dispersion paste in which 1 part by weight of carbon nanotubes are uniformly dispersed in 1 to 100 parts by weight of a solvent.

As the circuit board material, various materials selected from the group of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, thermoplastic resin, epoxy, thermosetting resin, aramid nonwoven fabric, glass woven fabric, and glass fabric woven fabric are used. Although it can be used, it is not limited to this.

The conductive paste 1 according to the present embodiment is arranged in a predetermined pattern on the surface of the circuit board, and forms a circuit pattern on the circuit board. The circuit pattern can be connected to various corresponding electronic components as well as general wiring formed with copper foil on a circuit board. In this way, a desired circuit board can be formed. In addition, the electronic component can be mounted on the circuit board by mounting the electronic component on the circuit pattern in a positional relationship such that the electrodes correspond to each other.

[Method of forming circuit board]
Next, a method for forming the conductive paste 1 on the surface of the circuit board 5 will be described. FIG. 2 is a process diagram when the conductive paste 1 is supplied to the surface of the circuit board 5.

First, as shown in FIG. 2A, a circuit board 5 is prepared.

Next, as shown in FIG. 2B, a mask 6 serving as a negative of the circuit pattern 7 is placed on the circuit board 5, and the conductive paste 1 is supplied onto the mask 6. As a method of forming a pattern with the conductive paste 1 on the circuit board 5, for example, various methods such as screen printing, ink jet, dispenser, impregnation, spin coating and the like can be used.

The carbon nanotubes 2 and the conductive particles 3 which are each component of the conductive paste 1 are dispersed in the curable resin 4. In the above state, since the carbon nanotubes 2 and the respective conductive particles 3 are spaced at an appropriate interval, the carbon nanotubes 2 and the conductive particles 3 are not in contact with each other.

Next, as shown in FIG. 2 (c), the conductive paste 1 is formed on the circuit board 5 and the mask 6 is removed, and then heat, light, etc. are applied to the circuit pattern 7 of the conductive paste 1. To activate the reducing agent. By doing so, the conductive paste 1 is cured in the pattern, and a desired circuit pattern 7 is formed on the circuit board 5.

As the curing of the curable resin 4 proceeds, the entire volume of the curable resin 4 contracts. As a result, the interval between the carbon nanotube 2 and each conductive particle 3 becomes small, and the carbon nanotube 2 enters between the narrowed conductive particles 3. By doing so, electrical contact can be formed between the conductive particles 3 and the carbon nanotubes 2. As a result, since the conductive component can be brought into contact as a whole, a conductive connection can be formed over the entire conductive particle 3 via the carbon nanotube 2.

2 (d), the electrodes (or terminals) of the electronic component 8 may be attached to the circuit pattern 7 in a positional relationship. At this time, the conductive paste 1 is increased in temperature to a predetermined temperature as necessary, and is disposed for a predetermined time. By doing so, the conductive paste 1 can be cured and the electronic component 8 can be mounted on the circuit board 5.

[Description of action and effect]
Next, functions and effects in the present embodiment will be described. The conductive paste 1 in the present embodiment is applied with heat, light, etc. after being supplied to the surface of the circuit board 5. In the process of supplying the conductive paste 1, the curing reaction of the curable resin 4 has not yet started. Therefore, the operation of supplying the conductive paste 1 has a relatively high degree of freedom with respect to time, supply operation, supply means, and the like. Can have.

Therefore, the conductive paste 1 can maintain sufficient fluidity and can be supplied in a predetermined pattern on the surface of the circuit board 5 by a general printing means. For example, as shown in FIG. 2B, the conductive paste 1 can be supplied on the mask 6 by placing a mask 6 serving as a negative of the circuit pattern 7 on the circuit board 5.

The conductive paste 1 in this embodiment is applied in a predetermined pattern on the surface of the circuit board 5, and a circuit pattern 7 is formed on the circuit board 5. The circuit pattern 7 can form a desired circuit board 5 by connecting various corresponding electronic components 8 and the like in the same manner as general wiring formed of copper foil on the circuit board 5. it can. Further, the electronic component 8 can be mounted on the circuit board 5 by mounting the electronic component 8 on the circuit pattern 7 in such a positional relationship that the electrodes correspond to each other.

When the conductive paste 1 according to the present embodiment is formed on the circuit board 5 as the circuit pattern 7, high adhesive strength can be realized with respect to the circuit board 5. For this reason, the circuit board 5 with high reliability can be formed.

Moreover, the conductive paste 1 of this embodiment is printed when the electronic component 8 is mounted by printing the circuit pattern 7 on the circuit board 5 and then placing the electronic component 8 and raising the temperature to a predetermined temperature. In addition, a high adhesive strength can be realized for the circuit board 5 and the electronic component 8.

[Fourth embodiment]
Next, the fourth embodiment will be described in detail. The present embodiment relates to a paste used for a field emission electrode (electron emission source electrode) having a composition different from that of the first embodiment, using the carbon nanotube-dispersed paste of the first embodiment, and a manufacturing method thereof.

The carbon nanotube serving as the electron emission source may be any of the carbon nanotubes described above. In particular, a carbon nanotube having a crystallinity with a D / G ratio of 0.2 or less measured by Raman spectroscopic analysis is preferable because of its high characteristics as an electron emission source and high durability. However, carbon nanotubes having good crystallinity have a defect that the dispersibility in a solvent is poor because they have few defects and few surface functional groups.

In the method for producing a carbon nanotube-dispersed paste of the present invention, in particular, the dispersibility of carbon nanotubes having good crystallinity can be dramatically improved by a simple method without using a surfactant or the like. .

The carbon nanotube dispersion paste prepared as described above is mixed with an inorganic substance such as glass powder for adhering the cathode electrode, an organic binder as a support member for the electrode structure, and a solvent for dissolving the organic binder to form a field emission electrode. Make the paste to be used.

Examples of the inorganic substance include glass frit, alumina, zirconia, titanium dioxide, and silica. Examples of the organic binder include cellulose resin, acrylic resin, ethylene vinyl acetate copolymer resin, polyvinyl butyral, polyvinyl alcohol, propylene glycol, urethane resin, melamine resin, phenol resin, alkyd resin, and the like. Is mentioned.

The carbon nanotube-dispersed paste of the present embodiment can uniformly disperse carbon nanotubes in a solvent (A) having a similar structure or a paste used for a field emission electrode. Therefore, when mixing and kneading with an inorganic or organic binder In addition, it is possible to minimize the influence of the solvent component in which the carbon nanotubes are dispersed decomposing or modifying the paste material used for the field emission electrode.

By mixing and kneading the carbon nanotube dispersion paste with an inorganic or organic binder such as glass frit, a paste used for a field emission electrode in which the carbon nanotubes are uniformly dispersed between the glass frit and the organic binder can be obtained. An electrode manufactured using the above-described paste has high dispersibility of carbon nanotubes, and thus has a large number of bright spots, is uniform, and emits light as a highly efficient electron emission source.

FIG. 3 is a perspective view schematically showing an example of the configuration of the cathode electrodes of the FED and FEL in the fourth embodiment.
As shown in FIG. 3, the field emission light-emitting device 9 according to the present embodiment includes an anode substrate 10, a cathode substrate 20, and a spacer 30.

The anode substrate 10 has a transparent substrate 11, an anode electrode 12 formed on the substrate 11, and a phosphor layer 13 formed on the anode electrode 12. In the present embodiment, an example in which a transparent electrode is applied as the anode electrode 12 will be described.

The cathode substrate 20 includes a substrate 21 made of a metal, a semiconductor, or an insulator, a cathode electrode 22, and an emitter electrode. The cathode electrode 22 is a conductive layer, and the emitter electrode is an electron emission layer. The spacer 30 is provided between the anode substrate 10 and the cathode substrate 20. For this reason, the space between the anode substrate 10 and the cathode substrate 20 is a vacuum.

The distance between the anode electrode 12 and the cathode electrode 22 is determined by inserting a spacer 30 between the anode substrate 10 and the cathode substrate 20. When the interelectrode distance between the anode electrode 12 and the cathode electrode 22 is too large, electrons are emitted to a place other than where the electrons should be emitted structurally, resulting in a decrease in luminous efficiency and discharge.

On the other hand, when the interelectrode distance between the anode electrode 12 and the cathode electrode 22 is too short, electrons can be easily emitted, but a voltage for sufficiently emitting the phosphor layer 13 cannot be obtained. From the above, the distance between the anode electrode 12 and the cathode electrode 22 is preferably 0.1 mm to 200 mm, more preferably 1 mm to 10 mm.

The anode electrode 12 is a transparent electrode made of, for example, ITO, ZnO, TiO ₂ , carbon nanotube, or the like. A phosphor such as that used in CRT (Cathode Ray Tube) can be applied to the phosphor layer 13. For example, a sulfide phosphor, an oxide phosphor, or a nitride phosphor that is an electron beam excited phosphor that emits fluorescence when irradiated with an electron beam can be used. The phosphor layer 13 can be formed by using, for example, a spray method, screen printing, hand coating printing, or sedimentation method. The film thickness of the phosphor layer 13 is preferably, for example, 0.1 μm to 100 μm.

The cathode electrode 22 is an electrode made of metal, conductive metal oxide, or the like. The metal used as the cathode electrode 22 is Ag, Au, Pt, Ti, Al, Cu, Cd, Pd, Zr, C, and the metal oxide is a simple substance or alloy selected from ITO, TiO ₂ and ZnO. Can be used.

The emitter electrode is an electron emission layer composed of a nanocarbon material such as carbon nanotube 2. As a method for applying the emitter electrode, for example, screen printing, spraying, hand-painting, ink jet, or the like can be applied. Further, the emitter electrode uses the carbon nanotube dispersion paste described in the first or second embodiment to improve the dispersibility of the carbon nanotubes in the electrode, and has a larger number of bright spots than the conventional emitter electrode, It emits light as a uniform and highly efficient electron emission source.

Hereinafter, examples and comparative examples will be shown, and the present embodiment will be described more specifically. However, the invention is not limited by the following examples.

Example 7
By mixing 1 part by weight of carbon nanotubes with 1000 parts by weight of 1,2-dichloroethane (boiling point 84 ° C.), carbon is irradiated by alternately irradiating 45 kHz, 100 W bath type ultrasonic waves and 20 kHz, 300 W probe type ultrasonic waves. A nanotube dispersion solution was prepared (Step 1A). As the carbon nanotube, a carbon nanotube with a good crystallinity having a D / G ratio of 0.2 or less as measured by Raman spectroscopy was used.

Next, 10 parts by weight of a carbon nanotube dispersion solution and terpineol (boiling point 218 ° C.) are mixed, while kneading using a three-roll mill, 1,2-dichloroethane is volatilized and solvent substitution is performed, and terpineol dispersion paste of carbon nanotubes (Step 2).

Next, the carbon nanotube / terpineol dispersion paste is mixed and kneaded with glass frit, ethyl cellulose, etc. by a three roll mill, and an electric field composed of 1 part by weight of carbon nanotubes, 7 parts by weight of glass frit, 2 parts by weight of ethyl cellulose, and a terpineol solvent. A paste used for the emission electrode was produced.

Next, the paste used for the field emission electrode is printed on the cathode electrode substrate on which the ITO film is formed by using a screen printer, dried at 80 ° C., and 1 × 5 × 10 ⁻³ Torr in vacuum at 500 ° C. Time firing was performed to produce a field emission electrode.

The phosphor layer 13 of the anode substrate 10 and the emitter electrode 23 of the cathode substrate 20 are provided opposite to each other with a space surrounded by the spacer 30 interposed therebetween, and the phosphor layer 13 and the emitter electrode 23 are vacuumed. is there.

When a positive electric field is applied from the cathode electrode 22 toward the anode electrode 12, the emitter electrode 23 emits electrons. The emitted electrons are accelerated by the potential difference between the cathode electrode 22 and the anode electrode 12 and irradiated onto the phosphor layer 13. As a result, the phosphor layer 13 emits light.

Since the anode electrode 12 is a transparent electrode, the phosphor layer 13 transmits light. Therefore, the light emitted from the phosphor layer 13 passes through the anode electrode 12 and the transparent glass substrate 11 and irradiates the outside. The result of electron emission using the field emission electrode prepared above is shown in FIG.

[Comparative Example 7]
Carbon nanotubes are mixed and kneaded with glass frit, ethyl cellulose, etc. in a three-roll mill, and paste used for a field emission electrode composed of 1 part by weight of carbon nanotubes, 7 parts by weight of glass frit, 2 parts by weight of ethyl cellulose, and terpineol solvent. Manufactured. The same materials as in Example 7 were used, such as carbon nanotubes.

However, in Comparative Example 7, the ratio of components other than the solvent in the paste used for the field emission electrode is the same as that in Example 7, but only the solvent (A) is used, and the above-described solvent replacement step (Step 2). ) Was not performed.

The paste used for the field emission electrode thus prepared was printed on a cathode electrode substrate on which an ITO film was formed using a screen printer, dried at 80 ° C., and vacuum of 5 × 10 ⁻³ Torr at 500 ° C. Was fired for 1 hour to prepare a field emission electrode. The result of electron emission using this is shown as a light emission photograph in FIG.

[Results of examination between Examples and Comparative Examples]
As shown in FIGS. 4 and 5, it can be seen that the field emission electrode of Example 7 has a significantly larger number of emission bright spots than the field emission electrode of Comparative Example 7.

That is, when carbon nanotube dispersed paste in which carbon nanotubes are uniformly dispersed in the solvent (A) before being mixed and kneaded with the paste material used for the field emission electrode is used, when this is mixed and kneaded at the same time In comparison, since the carbon nanotubes can be uniformly dispersed between the glass frit and the organic binder, the emission luminescent spot of the field emission electrode can be remarkably increased, and a field emission light emitting device with good emission characteristics can be produced.

The present invention also includes the following aspects.

(1)
Carbon nanotubes are dispersed in a solvent,
A solvent (A) having a boiling point of not less than 90% by volume and less than 99.9999% by volume and having a boiling point of not less than 150 ° C. in all the solvents;
A solvent (B) having a boiling point lower than that of the solvent (A) in the remaining volume% or less of the solvent (A);
Carbon nanotube dispersion paste containing.
(2)
The carbon nanotube-dispersed paste according to (1), wherein 2 parts by weight of the carbon nanotubes are dispersed in 1 to 100 parts by weight of the solvent.
(3)
A method for producing a carbon nanotube-dispersed paste according to (1) or (2),
A manufacturing method comprising a step of dispersing the carbon nanotubes in the solvent by combining a plurality of types of ultrasonic waves having at least one of frequency, intensity, and application method being different.
(4)
A method for producing a carbon nanotube-dispersed paste according to (1) or (2),
A step of dispersing the carbon nanotubes in the solvent (B) to form a carbon nanotube dispersion solution;
Replacing the solvent (B) of the carbon nanotube dispersion solution with the solvent (A) having a boiling point of 150 ° C. or higher;
A manufacturing method comprising:
(5)
A method for producing a carbon nanotube-dispersed paste according to (1) or (2),
Combining a plurality of types of ultrasonic waves having different frequencies, intensities, and application methods to disperse the carbon nanotubes in the solvent (B) to produce a carbon nanotube dispersion solution;
Replacing the solvent (B) of the carbon nanotube dispersion solution with the solvent (A) having a boiling point of 150 ° C. or higher;
A manufacturing method comprising:
(6)
The carbon nanotube dispersion paste according to (1) or (2), wherein the conductive particles and the binder are further dispersed.
(7)
A method for producing a carbon nanotube-dispersed paste comprising:
(3) to produce the carbon nanotube-dispersed paste by the production method according to any one of (5),
A production method in which conductive particles and the binder are mixed and kneaded in the produced carbon nanotube dispersion paste and dispersed together with the carbon nanotubes.
(8)
An inorganic material for bonding the cathode electrode;
An organic binder as a support member of the electrode structure;
A solvent for dissolving the organic binder,
The carbon nanotube dispersion paste according to (1) or (2), which is further dispersed and used for forming an electron emission source electrode.
(9)
A method for producing a carbon nanotube-dispersed paste comprising:
(3) to producing the carbon nanotube-dispersed paste by the production method according to any one of (5),
A manufacturing method in which the inorganic substance, the organic binder, and the solvent are mixed and kneaded with the produced carbon nanotube dispersion paste and dispersed together with the carbon nanotubes.
(10)
(6) or an emitter electrode using the carbon nanotube-dispersed paste according to any one of (8),
A phosphor layer that is provided to face the emitter electrode and emits light by collision of electrons emitted from the emitter;
A field emission light emitting device having:

This application claims priority based on Japanese Patent Application No. 2010-28284 filed on Dec. 20, 2010, the entire disclosure of which is incorporated herein.

Claims

Carbon nanotubes are dispersed in a solvent,
A solvent (A) having a boiling point of not less than 90% by volume and less than 99.9999% by volume and having a boiling point of not less than 150 ° C. in all the solvents;
A solvent (B) having a boiling point lower than that of the solvent (A) in the remaining volume% or less of the solvent (A);
Carbon nanotube dispersion paste containing.
2. The carbon nanotube dispersion paste according to claim 1, wherein 1 part by weight of carbon nanotubes is dispersed in 1 to 100 parts by weight of the solvent.
The carbon nanotube-dispersed paste according to claim 1 or 2, wherein the boiling point of the solvent (B) is 10 ° C or more lower than the boiling point of the solvent (A).
The carbon nanotube is any one selected from the group consisting of single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanohorns, carbon nanohorn aggregates, and carbon nanohorn composites having a structure in which carbon nanotubes and carbon nanohorns are joined. The carbon nanotube dispersion paste according to any one of claims 1 to 3, comprising one or more carbon nanostructures.
The carbon nanotube dispersion paste according to any one of claims 1 to 4, further comprising conductive particles and a binder.
The carbon nanotube dispersion according to claim 5, wherein the material of the conductive particles is any one selected from the group consisting of silver, copper, gold, tin, indium, nickel, and palladium, or a mixture or alloy of a plurality of types. paste.
The carbon nanotube-dispersed paste according to claim 5 or 6, wherein the binder is a curable resin, and the curable resin is a thermosetting resin or a photocurable resin.
The curable resin is at least one selected from the group consisting of an epoxy resin, an acrylic resin, a phenol resin, a polyimide resin, a silicone resin, a polyurethane resin, and an unsaturated polyester resin. 7. The carbon nanotube dispersion paste according to 7.
The carbon nanotube dispersion paste according to any one of claims 1 to 8, which is used for forming a field emission electrode.
A circuit board having a circuit pattern formed on a substrate using a conductive paste containing the carbon nanotube-dispersed paste according to any one of claims 1 to 9.
11. The substrate is formed of one or more materials selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, epoxy resin, aramid nonwoven fabric, glass woven fabric, and glass fabric woven fabric. Circuit board as described in.
An emitter electrode comprising the carbon nanotube-dispersed paste according to any one of claims 1 to 9 as an electron emission source.
13. A field emission light-emitting device comprising: the emitter electrode according to claim 12; and a phosphor layer provided opposite to the emitter electrode and emitting light when electrons emitted from the emitter collide with each other.
A step of dispersing the carbon nanotubes in a solvent (B) lower than the solvent (A) having a boiling point of 150 ° C. or higher to obtain a carbon nanotube dispersion solution;
Replacing the carbon nanotube dispersion solution with the solvent (A) to obtain a carbon nanotube dispersion paste;
The manufacturing method of the carbon nanotube dispersion | distribution paste which has this.
The method for producing a carbon nanotube-dispersed paste according to claim 14, wherein, in the step of obtaining the carbon nanotube dispersion solution, the carbon nanotubes are dispersed in the solvent (B) by irradiating ultrasonic waves.
The method for producing a carbon nanotube-dispersed paste according to claim 14 or 15, wherein in the step of obtaining the carbon nanotube-dispersed solution, two or more kinds of ultrasonic waves having at least one of frequency and intensity are alternately irradiated.
The method for producing a carbon nanotube-dispersed paste according to any one of claims 14 to 16, wherein in the step of obtaining the carbon nanotube-dispersed paste, the solvent (B) is volatilized by mixing and kneading.
The carbon nanotube dispersion paste according to any one of claims 14 to 17, further comprising a step of simultaneously mixing and kneading the carbon nanotube dispersion paste, conductive particles, and a binder after the step of obtaining the carbon nanotube dispersion paste. Production method.
After the step of obtaining the carbon nanotube dispersion paste, a first mixing and kneading step of mixing and kneading the conductive particles and the binder,
After the first mixing and kneading step, a second mixing and kneading step of adding and mixing and kneading the carbon nanotube dispersion paste,
The method for producing a carbon nanotube-dispersed paste according to any one of claims 14 to 17, further comprising:
The method for producing a carbon nanotube-dispersed paste according to any one of claims 14 to 17, further comprising, after the step of obtaining the carbon nanotube-dispersed paste, a step of adding the kneaded paste to a pre-kneaded silver paste and kneading. .