JP4432440B2 - Field electron emission electrode ink and method of manufacturing field electron emission film, field electron emission electrode and field electron emission display device using the same - Google Patents

Description

  The present invention relates to a field electron emission electrode ink used for applications such as a field emission display, a scanning tunneling microscope, or a field emission microscope, and more particularly to a field electron emission electrode ink containing a carbon nanotube structure.

  Carbon nanotube research began in 1991 when Iijima et al. Discovered multi-walled carbon nanotubes as a byproduct of fullerenes. Multi-walled carbon nanotubes are included in the cathode deposit during the synthesis of fullerenes by arc discharge of graphite rods. The multi-walled carbon nanotubes have a concentric cylindrical structure with rounded graphite sheets (graphene sheets). It is. Later, in 1993, Iijima et al. Succeeded in synthesizing soot containing single-walled carbon nanotubes with a diameter of about 1 nm by arc discharge using iron powder as a catalyst. At the same time, a single-walled carbon nanotube with a diameter of 1.2 nm was discovered by arc discharge using cobalt as a catalyst. A single-walled carbon nanotube has a structure in which a single graphite sheet (graphene sheet) is wound in a cylindrical shape, and has a diameter of several nanometers. A metal catalyst is not required for the synthesis of multi-walled carbon nanotubes, but a metal catalyst is indispensable for the synthesis of single-walled carbon nanotubes. Moreover, single-walled carbon nanotubes having different diameters can be selectively synthesized depending on the type of metal catalyst.

  Carbon nanotubes can be applied as electronic materials and nanotechnology in various fields using their geometric and physicochemical characteristics. In recent years, examples of such applications include flat panel displays (field electron emission type), field emission electron sources, scanning probe microscope probes, nano-order semiconductor integrated circuits, hydrogen gas storage materials, and nano cylinders. In particular, field electron emission electrodes utilizing high field electron emission efficiency have attracted attention.

  Examples of using such a high field electron emission electrode include a field emission display (FED), a scanning tunneling microscope (STM) or a field emission microscope (FEM). Research is being conducted for the purpose of application to these uses.

  The field electron emission electrode can overcome the energy barrier by the tunnel phenomenon because the energy barrier on the metal material surface or the semiconductor material surface is lowered by applying an electric field higher than the threshold value to the metal material or semiconductor material in a vacuum. Since electrons increase, the phenomenon that electrons are emitted in a vacuum even at room temperature is used.

  Conventionally, as a process for manufacturing an electrode of a field emission display (FED), for example, advanced processing technology applied to a semiconductor manufacturing process such as photolithography, sputtering, or vapor deposition has been used. The electrode is manufactured. As a typical example of the production, an insulating layer is formed on the surface of the electrode substrate, and an electrode film for electron extraction is formed on the surface of the insulating layer. A resist is applied thereon, a mask is formed in a predetermined shape, and holes are formed in each electrode array by wet etching. Next, an electrode material for electron emission is deposited to form an electron emission electrode, and then the resist is removed to complete the electrode. Molybdenum (Mo) is used as an electrode material for electron emission, and is made by process control so as to form a conical shape. The reason for the conical shape is that the field electron emission efficiency is increased due to the sharp tip. In order to form such a special shape, complicated control in vacuum and a large number of machining processes are required, and the machining process takes a long time.

  As described above, in order to use the FED as a display in the conventional technique, there is a problem in the processing process, and it is difficult to increase the size of the electrode. For this reason, there is a demand for development of a technique that can be easily controlled with a small number of processing processes in vacuum and a field electron emission material that can be used therefor.

  Carbon nanotubes are promising as a material for the above requirements because they have a long and narrow tip, and when a voltage is applied, a strong electric field is generated at the tip and electrons can be emitted at a relatively low voltage.

  The method of using carbon nanotubes as a field electron emission electrode can realize a more stable current with a lower degree of vacuum, unlike a method of making a very elaborate electron emission electrode through a number of conventional processes. . This is considered due to the fact that the tips of the carbon nanotubes are very thin and the work function is low due to the very high conductivity. Since each carbon nanotube can be a micro electron gun, a large number of electron guns can be arranged per unit area. A method of growing carbon nanotubes directly on the substrate has also been studied.

  A conventional method for manufacturing a field electron emission source using carbon nanotubes is a chemical vapor deposition (CVD) method, which directly controls the length, thickness, etc. of the cathode substrate. An electrode is created by applying the carbon nanotube produced by the existing method and an appropriate solvent or adhesive to the substrate, and drying it. A method of creating a file has been attempted.

  Among these, there are the following techniques using an ink in which carbon nanotubes are mixed with an appropriate solvent or adhesive.

(1) Technology that uses organic resin as an adhesive This is a method in which carbon nanotubes are mixed together with conductive particles using an organic resin as an adhesive to create ink. Create a high ink. A screen is selected so as to obtain a target film thickness, and the film is formed by printing. In order to ensure conductivity, metal particles and ITO particles are dispersed in the solution. The obtained paste is formed into a film by a screen printing method.
The dried film is baked at an appropriate temperature, and after carbonizing the organic resin, carbon nanotubes are brought out on the surface by an appropriate surface treatment (see, for example, Patent Documents 1 and 2).

(2) Technology Using Inorganic Adhesive Sodium salt such as silicic acid or boric acid, potassium salt, lithium salt or the like generally called water glass or silica dispersed colloid is used as the adhesive. In general, ions such as sodium, potassium and lithium are removed, and ammonia or the like is added for pH adjustment. Water is used as a solvent, and carbon nanotubes are mixed in an appropriate composition to prepare an ink. The ink is applied by the screen printing method in the same manner as described above, and is subjected to surface treatment after firing (see, for example, Patent Document 3).

(3) Method of using solder etc. A method of fixing carbon nanotubes on a substrate using a metal solder containing at least one element such as Sn, In, Bi, Pb or the like as an adhesive. Carbon nanotubes are thoroughly mixed with the metal solder, carbon-soluble metal, carbide-forming metal, low-melting-point metal, or conductive polymer (silver paste), and finally fired at 800 ° C. in vacuum after film formation. (See, for example, Patent Document 4).

JP 2001-176380 A JP 2001-93404 A Japanese Patent Laid-Open No. 2000-100308 Japanese Patent Laid-Open No. 2000-141056

  On the other hand, when preparing a dispersion for producing a field electron emission source using conventional carbon nanotubes, mixing is performed with sufficient shearing force to disperse the carbon nanotubes in a high-viscosity paste. Sometimes the carbon nanotubes once dispersed in the paste hardly reaggregate. This is because the resistance to viscosity by the paste is larger than the attractive force acting during reaggregation. In this case, no special dispersion stabilizer is required.

  When a dispersion having a different coating method and a low viscosity is produced, the attractive force between the carbon nanotubes is larger than the resistance of the dispersion medium, which makes the dispersion unstable and causes re-aggregation and precipitation. As a countermeasure, a dispersion aid is used. Thereby, a functional molecule can be adsorbed on the surface of the carbon nanotube, and the carbon nanotube can be stably present in the dispersion medium by utilizing an electric repulsion force or a steric repulsion force of a molecular structure.

  Therefore, by using a dispersant that easily reacts with the carbon nanotube surface, it is possible to supply ink with excellent dispersion stability and to form a uniform film when a field electron emission electrode is formed by a coating method. . Further, when forming the field electron emission electrode, the film can be made as thin as possible, and it becomes a material superior to the lamination process, high definition, low degassing, and the like.

Examples of techniques using such a dispersant are as follows.
(1) Method of using sodium dodecyl sulfate as a dispersant This is a method of adding and dispersing sodium dodecyl sulfate as a dispersant in water, which enhances the dispersion effect by the repulsive force of dodecyl sulfate groups adsorbed on the carbon nanotube surface. it can.
(2) Method of using sodium dodecylbenzene sulfate as a dispersant By using sodium dodecylbenzene sulfate as a dispersant in water, it is possible to create a dispersion that is significantly more stable than other dispersants. .
(3) Method using polyoxyethylene-10-octylphenyl ether Dispersion is carried out by adsorption action and steric repulsion due to the interaction between the carbon nanotubes and the phenyl group of the dispersant.
(4) Method using Octadecylamine By reacting a carboxyl group on the surface of a carbon nanotube with an amine group, molecules can be adsorbed and dispersion stability can be obtained by a steric hindrance effect.

  In the field electron emission display, since a plurality of minute electron guns are arranged in each pixel, the size of the pixel can be reduced as the distance between the electron gun and the anode electrode, that is, the phosphor is smaller. Since the electrons emitted from the electron gun spread slightly from the emission source and collide with the phosphor, if the field electron emission electrode has the same characteristics, the spread can be suppressed to be smaller as the phosphor is closer. In order to reduce the size of the pixel, it is necessary to make the entire electron gun small. To that end, it is also necessary to make the insulating film and the carbon nanotube coating film thin.

  However, each of the conventional techniques as described above has problems. That is, when an organic resin is used as an adhesive, it can be applied only with a thick film in order to ensure adhesion even after firing. In addition, since the inorganic adhesive has high film resistance, the distribution of electron emission sources is uneven, and water is used as a solvent. Therefore, the film has a large residual gas after firing. In both cases, the conductivity of the film is ensured by adding conductive particles to the ink, so the film thickness depends on the size of the conductive particles. That is, when the size of the conductive particles is larger than that of the coating film, the resistance value in the plane of the film becomes uneven. For this reason, it has been difficult to form a sufficiently thin field electron emission thin film with the conventional ink composition.

  Further, regarding the residual gas in the field electron emission film, in the field electron emission display, the electrons generated from the cathode are accelerated toward the anode, and the electrons are collided with the phosphor to be excited to emit light. In order to generate electrons, the atmosphere between the cathode and anode must be evacuated. Since the electrode coated with the carbon nanotube-containing ink is used as a cathode, it is placed in a vacuum.

  Therefore, it is necessary that the applied ink is sufficiently discharged before being sealed in a vacuum. When an organic solvent is used, it is indispensable not only to dry but also to calcinate to a sufficient temperature. Also, when an inorganic adhesive is used, it is necessary to sufficiently remove water used as a solvent.

  However, the solvent contained in the adhesive, particularly moisture, is very difficult to remove and remains on the display substrate as a residual gas. For this reason, the electron flow emitted from the carbon nanotube becomes very unstable. When this phenomenon is considered as a display, it may cause flickering of the screen.

  Furthermore, regarding the dispersant, it was necessary to develop a dispersant capable of maintaining the dispersion state more stably corresponding to various ink properties.

  The present invention has been made in response to the above-described conventional circumstances, and can easily produce a thin-film field electron emission film having high electron emission efficiency, thereby increasing the definition of the field electron emission display. It is an object of the present invention to provide a field electron emission electrode ink that can be realized and has good dispersibility.

  The present invention firstly includes 0.005 to 5% by weight of a carbon nanotube structure, a thermally decomposable metal compound, a solvent, and a dispersant, wherein the dispersant is an organic amine compound or an organic ammonium compound. A field electron emission electrode ink comprising a combination of alkylbenzene sulfonic acid, alkyl sulfonic acid or a salt thereof.

  In the present invention, when an ink is produced, a thermally decomposable metal compound (an organometallic compound, a metal salt, or an organometallic salt compound) is used as an adhesive, so that a film with less residual gas can be formed after firing. By coating with a thin film, a field electron emission electrode coating film showing a sufficient electron emission amount can be formed. In the conventional method, since the coating film is thick, when used as a display, the resistance to the post-processing process was low, but a coating film in which the electron-emitting material is sufficiently dispersed in the thin film can be formed. The thickness of the electron-emitting electrode portion can be made thinner, which can contribute to higher definition of the display.

  The organic amine compound used in the present invention is preferably a primary, secondary or tertiary amine having a linear or branched alkyl group having 4 or more carbon atoms, and the organic ammonium compound has the number of carbon atoms. Preferably has 4 or more linear or branched alkyl groups. The alkylbenzene sulfonic acid and the alkyl group of the alkyl sulfonic acid are preferably straight-chain or branched alkyl groups having 3 or more carbon atoms.

  Among the dispersants, the concentration of the organic amine compound or the organic ammonium compound in the ink is preferably 0.001 to 1% by weight, and the concentration of the alkylbenzene sulfonic acid, the alkyl sulfonic acid or a salt thereof in the ink is 0.00. It is preferable that it is 001 to 1 weight%.

  As the thermally decomposable metal compound, an organometallic compound, a metal salt or an organometallic salt compound is preferable. The thermally decomposable metal compound is preferably composed of a plurality of metals. The thermally decomposable metal compound is particularly preferably at least one additive metal selected from Sn and In and Sb. Further, it is particularly desirable that the selected additive metals are Sn and In, and the ratio of Sn to In is 6 atomic% or more.

  The concentration of the thermally decomposable metal compound in the ink is preferably 0.1 to 50% by weight.

  In the ink of the present invention, the chelating agent is further contained, the viscosity is 0.001 to 0.5 Pa · s, and the solid content concentration is 0.5 to 50% by weight, respectively. preferable.

  Second, the present invention is a method for producing a field electron emission film used for a field electron emission electrode, comprising 0.005 to 5% by weight of a carbon nanotube structure, a thermally decomposable metal compound, a solvent, A dispersion agent, and the dispersion agent has a step of applying an ink, which is a combination of an organic amine compound or an organic ammonium compound, and an alkylbenzene sulfonic acid, an alkyl sulfonic acid, or a salt thereof onto an electrode substrate. A method for producing a field electron emission film according to claim 11 (claim 11).

  Thirdly, the present invention relates to a method for producing a bipolar field electron emission electrode comprising a cathode electrode and a field electron emission film sequentially formed on a support, wherein the field electron emission film is produced by 0.005 to 5% by weight of a nanotube structure, a thermally decomposable metal compound, a solvent, and a dispersant, wherein the dispersant is an organic amine compound or an organic ammonium compound, alkylbenzene sulfonic acid, alkyl sulfonic acid Or a method of manufacturing a field electron emission electrode, comprising: a step of applying an ink comprising a combination of the salt and the salt on the cathode electrode; and a step of baking the coating film. 12).

  Fourth, the present invention provides a cathode electrode, an insulating layer, and a gate electrode that are sequentially formed on a support, an opening formed in common with the insulating layer and the gate electrode, and at least the cathode electrode in the opening. A method of manufacturing a triode-type field electron emission electrode comprising a formed field electron emission film, wherein a carbon nanotube structure is added at 0.005 to 5% by weight in a manufacturing process of the field electron emission film, An ink comprising a decomposable metal compound, a solvent, and a dispersant, wherein the dispersant is a combination of an organic amine compound or an organic ammonium compound and an alkylbenzene sulfonic acid, an alkyl sulfonic acid or a salt thereof. A method for producing a field electron emission electrode, comprising: a step of coating on a cathode electrode; and a step of baking the coating film. 3).

  Fifthly, the present invention provides a field electron emission display device in which a cathode panel provided with a plurality of field electron emission electrodes and an anode panel provided with a phosphor layer and an anode electrode are joined at the respective peripheral portions. A method of manufacturing a field electron emission display device, wherein the field electron emission electrode is manufactured by the method according to claim 12 or 13 (claim 14).

According to the ink for a field electron emission electrode of the present invention, by using a thermally decomposable metal compound, it is possible to ensure both adhesion to the substrate and imparting electrical conductivity, and the residual gas after firing. A small number of films can be formed. For this reason, since it is not necessary to ensure the conductivity of the film by adding conductive particles as in the prior art, it is possible to form a field electron emission film that is thin and excellent in smoothness and has high electron emission characteristics. . Furthermore, by selecting an appropriate amount of dispersant added, composition, structure, and solvent, it becomes a dispersion with excellent dispersibility of carbon nanotubes and high dispersion stability, and uniform film quality without aggregation of carbon nanotubes on the surface. Thus, a field electron emission film having high electron emission characteristics can be formed.
If this field electron emission film is used, a field electron emission display device having high-definition pixels can be provided.

Next, embodiments of the present invention will be described in detail.
(1) Embodiment 1 (ink for field electron emission electrode)
In the present invention, the carbon nanotube structure means a carbon nanotube and / or a carbon nanofiber. In the present invention, carbon nanotubes or carbon nanofibers may be used, or a mixture thereof may be used.

  The difference between carbon nanotubes and carbon nanofibers is their crystallinity. A carbon atom having an sp2 bond usually constitutes a six-membered ring from six carbon atoms, and a group of these six-membered rings constitutes a carbon graphite sheet. A carbon nanotube has a tube structure in which the carbon graphite sheet is wound. Single-walled carbon nanotubes having a structure in which a single-layer carbon graphite sheet is wound may be used, or multi-walled carbon nanotubes having a structure in which two or more layers of carbon-graphite sheets are wound may be used. On the other hand, carbon nanofibers are those in which carbon graphite sheets are not wound and fragments of carbon graphite sheets overlap to form a fiber. Although the difference between the carbon nanotube or carbon nanofiber and the carbon whisker is not clear, the diameter of the carbon nanotube or carbon nanofiber is generally 1 μm or less, for example, about 1 nm to 300 nm.

  Moreover, it is preferable that the carbon nanotube and carbon nanofiber which are carbon nanotube structures are powdery macroscopically. As a method for producing carbon nanotubes or carbon nanofibers, various CVD methods such as PVD methods such as well-known arc discharge methods and laser ablation methods, plasma CVD methods, laser CVD methods, thermal CVD methods, vapor phase synthesis methods, and vapor phase growth methods Can be mentioned.

  A preferable size of the carbon nanotube structure used in the present invention is 0.7 to 100 nm in diameter and 0.5 to 100 μm in length.

  In the present invention, the blending amount of the carbon nanotube structure is preferably 0.005 wt% or more and 5 wt% or less in the total amount of ink.

  In the present invention, by preparing a predetermined ink using a solvent, particularly an organic solvent, together with a thermally decomposable metal compound that becomes an inorganic substance upon firing, generation of residual gas can be suppressed and sufficient adhesion can be ensured. . By using an adhesive with a small residual gas, electron emission is stabilized and the image does not become unstable when used as a display. In addition, since the metal compound is thermally decomposed by firing to form a dense inorganic film, there is almost no damage to the coating film during post-processing when a display is manufactured. In the present invention, since conductivity can be imparted to the adhesive itself, ink design is facilitated, and even when insulating particles are added, the resistance value of the coating film does not increase significantly.

  Further, in the ink of the present invention, by using a thermally decomposable metal compound, a field electron emission film having desired characteristics can be formed without blending a particulate conductive material in the ink.

Examples of the metal compound include organometallic compounds (including organic acid metal compounds), metal salts, and organometallic salt compounds.
Examples of metal salts include halides, nitrates, and acetates. In the present invention, halides are particularly effective among the above metal salts. Examples of the organic acid metal compound solution include an organic tin compound, an organic indium compound, an organic zinc compound, and an organic antimony compound dissolved in an acid (for example, hydrochloric acid, nitric acid, or sulfuric acid) and diluted with an organic solvent. be able to. Moreover, as an organometallic compound solution, what melt | dissolved the organic tin compound, the organic indium compound, the organic zinc compound, and the organic antimony compound in the organic solvent can be illustrated, for example. An organometallic salt compound having both an organic chain, a halogen and a metal can also be used as the thermally decomposable metal compound.

  In addition to indium (In), tin (Sn), and antimony (Sb), the metal elements that form the thermally decomposable metal compound that is a component of the field electron emission electrode ink of the present invention include zinc, aluminum, gold, silver, Examples thereof include silicon, germanium, cobalt, zirconium, titanium, nickel, platinum, and manganese. In addition, the metal compound that is a component of the ink of the present invention is preferably a compound composed of a plurality of metals from the viewpoint of reducing the threshold value. Specific examples thereof include indium-tin, tin-antimony and the like as in Examples described later. Further, a combination of a metal such as tin-fluorine (F) and a halogen may be used. In particular, one of the single or plural metals is preferably Sn from the viewpoint of affinity with the dopant.

  Here, when In—Sn is combined, the mixing ratio is preferably 6 or more Sn atoms with respect to 100 In atoms. When Sn—Sb is combined, the mixing ratio is preferably 4 or more with respect to Sn atoms 100. When Sn—F is combined, the mixing ratio is preferably 4 or more F atoms with respect to 100 Sn atoms.

  In addition, the functional group of the organic chain that forms the above organometallic (salt) compound by combining with a metal element is a linear or side chain alkyl group, alkoxy group, ester group, carbonyl group, ether group, amide group, benzoyl group Group, phenyl group, epoxide, amino group, amide group and the like.

  Examples of thermally decomposable metal compounds that can be used as the ink component of the present invention include dibutyltin diacetate, tetrachlorotin, tetrabutoxytin, indium chloride, triphenylantimony, indium triacetate, indium triacetate hydrate. , Indium acetylacetonate, indium halide, tri-tert-butoxy indium, trimethoxy indium, triethoxy indium, triisopropoxy indium, etc. one or two types of alkoxy groups, alkyl groups, acetyl groups, halogens, phenyl groups, etc. Examples of such compounds include bonded compounds, compounds in which one or two alkoxy groups, alkyl groups, acetyl groups, halogens, phenyl groups, and the like are bonded, such as tin halide, tetraethoxytin, tetraisoporopoxytin, and tetrabutoxytin.

  In the present invention, the amount of the thermally decomposable metal compound is preferably 0.1% by weight or more and 50% by weight or less, more preferably 0.4% by weight or more and 49% by weight.

  The dispersant of the present invention comprises a combination of a dispersant 1 that is an organic amine compound or an organic ammonium compound and a dispersant 2 that is an alkylbenzene sulfonic acid, an alkyl sulfonic acid or a salt thereof.

Next, the dispersant will be described in detail. As the dispersion mechanism of the particles by the dispersant, the particles are stabilized by the reaction with the particle surface. Therefore, the particles must have an appropriate structure depending on the structure of the particles, the functional groups on the surface, the solubility of the dispersant in the solvent, etc. It is necessary to select.
In particular, particles having a large length with respect to the diameter, such as a carbon nanotube, a so-called aspect ratio, and few functional groups having a chemical bond on the surface have a small dispersion effect with a conventional dispersant. Various types of structures have been studied as dispersants for carbon nanotubes. However, carbon nanotubes can be prevented from reattaching due to physical adsorption force by adhering to the surface at a high concentration, and So far, no dispersant has been confirmed that can achieve both stable dispersion at a concentration (particularly a low concentration).

  That is, it is possible to create an ink in a dispersion state to some extent by using a conventional dispersant, but when creating a low concentration ink, the dispersion effect is higher than in the case of a high concentration. It is necessary to use a dispersant, and it is rare that the dispersion state is maintained for a long time under normal mixing conditions of the dispersant.

In particular, when used in a field emission display as in the present invention, it is preferable that the dispersion state is maintained for a long time with a dispersion having a low carbon nanotube concentration. However, it is difficult to satisfy a desired requirement with the existing dispersant. there were. For example, the above sodium dodecyl sulfate, polyoxyethylene, amine, etc. have a high dispersion effect but low stability. In particular, at a low concentration, the solvent and the carbon nanotube are separated in a short time after appropriate dispersion treatment. There were many things. Thus, when the dispersion stability of the ink is low, the dispersibility is lowered during large-area coating or the like, which causes uneven coating.
Further, although it is possible to form a thin film by creating a high-density ink and using a specific coating method, there are many cases where there are restrictions on the object to be coated and the size.

  In view of such a situation, the inventors added carbon nanotubes to a solution obtained by diluting a dispersant with a solvent to an appropriate concentration, and when performing a suitable treatment to prepare a carbon nanotube dispersion, By considering the reactivity with the dispersant, it is considered possible to create an ink with good dispersibility and high stability, and as a result of examining the ink composition from such a viewpoint, as described above, It was found that when used in combination with Dispersant 1 and Dispersant 2, an ink with very good dispersion stability and dispersion state can be obtained.

  Of the dispersant 1, the organic amine compound is preferably a primary, secondary or tertiary amine having a linear or branched alkyl group having 4 or more carbon atoms, and the organic ammonium compound has a carbon atom number of It is preferable that it has 4 or more linear or branched alkyl groups.

  Examples of the dispersant that can be used as the ink component of the present invention include, as the dispersant 1, octadecylamine (ODA), dodecyldimethylamine (DDMA), dodecyltrimethylammonium chloride (DTMAC), dioctyldimethylammonium chloride ( DODMAC), methyltrioctadecanyl ammonium chloride (MTOAC), dimethyldioctadecanyl ammonium chloride (DMDOAC), and the like.

  Moreover, in the dispersing agent 2, the number of carbon atoms of the alkyl group of alkylbenzenesulfonic acid and alkylsulfonic acid is preferably 3 or more, and more preferably 4-21. The most preferable dispersant 2 is dodecylbenzenesulfonic acid (salt).

In this invention, the compounding quantity of the dispersing agent 1 is 0.001-1 weight%, Preferably it is 0.004-0.75 weight%.
Moreover, the compounding quantity of the dispersing agent 2 is 0.001-1 weight%, Preferably it is 0.004-0.75 weight%.

  As the solvent that is the ink component of the present invention, for example, an organic solvent such as ethyl alcohol, butyl acetate, toluene, isopropyl alcohol, or water can be used, and an organic solvent is preferable. The blending amount is not particularly limited as long as the ink viscosity is described later.

  The ink of the present invention preferably further contains a chelating agent. By blending the chelating agent, the dispersibility of the thermally decomposable metal compound is increased (the stability of the dispersed state is improved), so that a field electron emission film with more uniform characteristics can be produced with a high yield. .

  Examples of the chelating agent include ethylenediamine, pyridine, propylenediamine, diethylenetriamine, triethylenetetramine, 2,2'-bipyridine, 1,10-phenanthroline, ethylenediaminetetraacetate ion, dimethylglyoximato, glycinato, triphenylphosphine, cyclopenta Chelating agents such as dienyl are mentioned.

  In addition to the above components, the ink according to the present invention may contain a dispersant and a surfactant. Further, from the viewpoint of increasing the thickness of the matrix, an additive such as carbon black may be added to the metal compound solution. Moreover, although it is not necessary to mix | blend a particulate-form electroconductive substance in an ink for the above-mentioned reason, addition of this electroconductive substance is not excluded.

  As an example of a method for preparing an ink for forming a field electron emission film according to the present invention, a carbon nanotube structure is uniformly dispersed in a solution obtained by diluting the above pyrolyzable metal compound with a solvent to an appropriate concentration. Can be mentioned. The film-forming ink can also be produced by uniformly dispersing the carbon nanotube structure together with a thermally decomposable metal compound in an appropriate solvent.

  Also, by setting the viscosity of the ink to 0.001 to 0.5 Pa · s, when this ink is applied on the electrode substrate, a field electron emission film coating film that is a thin film is formed with a more uniform film thickness. It becomes possible to do. The solid content concentration of the ink is preferably 0.5 to 50% by weight.

(2) Embodiment 2 (field electron emission film)
The field electron emission film according to the present invention can be obtained by applying the above-described field electron emission electrode ink on an electrode and baking it. Examples of the coating method include spray coating, die coating, roll coating, dip coating, curtain coating, spin coating, and gravure coating. Spray coating is particularly preferable. The field electron emission film is fired after a coating film is formed on the electrode by the above method. Here, preferable baking conditions for the ink coating film are appropriately set in consideration of the composition of the metal compound that is a component of the ink. In general, the baking temperature is preferably in the range of 300 ° C to 600 ° C. Since the decomposition reaction of the organic functional group or the halogen proceeds at a relatively low temperature, it becomes possible to use a low-melting glass as the substrate. By baking, the thermally decomposable metal compound that is a component of the ink is decomposed, and inorganic substances, particularly metal oxides, metal halide oxides, and free metals, which differ depending on the type of metal, are generated. For example, tin oxide is produced from DBTDA (dibutyltin diacetate), and ITO (indium tin oxide) is produced from a mixture of IC (indium chloride) and TCT (tetrachlorotin). In addition, it can replace with baking and can also apply UV irradiation.

  It is particularly preferable that the field electron emission film always contains Sn. Since Sn has a high affinity for the dopant, an electrode film having uniform physical properties can be easily formed. Examples of the field electron emission film containing metallic tin include ITO, FTO (fluorine tin oxide), and ATO (antimony tin oxide).

(3) Embodiment 3 (bipolar field electron emission electrode / field electron emission display)
The field electron emission electrode according to the present embodiment will be described with reference to FIGS. The field electron emission electrode is used in a field electron emission display device as shown in FIG. 2 and 3, the cathode electrode 11 provided on the support 10 and a field electron emission film 15 provided on the cathode electrode 11 are formed. The field electron emission film 15 is composed of a matrix (a pyrolysis product of a metal compound) 21 and a carbon nanotube structure embedded in the matrix 21 in a state where the tip portion protrudes. Here, the manufacturing method of the field electron emission film is based on the second embodiment already described.

  As shown in FIG. 1, the display device according to the present embodiment includes a cathode panel CP provided with a plurality of field emission electrodes, and a phosphor layer 31 and an anode panel AP joined together at their peripheral portions. It has a plurality of pixels. In the cathode panel CP in the display device of the present embodiment, a large number of electron emission regions composed of a plurality of field emission electrodes as described above are formed in an effective region in a two-dimensional matrix.

  A through hole (not shown) for evacuation is provided in the ineffective region of the cathode panel CP, and a chip tube (not shown) that is sealed after evacuation is connected to the through hole. . The frame 34 is made of ceramics or glass and has a height of, for example, 1.0 mm. In some cases, only the adhesive layer can be used instead of the frame body 34.

  Specifically, the anode panel AP is formed on the substrate 30, the phosphor layer 31 formed on the substrate 30 according to a predetermined pattern (for example, a stripe shape or a dot shape), and the entire effective region, for example. The anode electrode 33 is made of an aluminum thin film. A black matrix 32 is formed on the substrate 30 between the phosphor layer 31 and the phosphor layer 31. The black matrix 32 can be omitted. Further, when assuming a monochromatic display device, the phosphor layer 31 is not necessarily provided according to a predetermined pattern. Furthermore, an anode electrode made of a transparent conductive film such as ITO may be provided between the substrate 30 and the phosphor layer 31, or an anode electrode 33 made of a transparent conductive film provided on the substrate 30 and an anode Light reflection made of phosphor layer 31 and black matrix 32 formed on electrode 33 and aluminum (Al) formed on phosphor layer 31 and black matrix 32 and electrically connected to anode electrode 33 It can also comprise a conductive film.

  One pixel has a rectangular cathode electrode 11 on the cathode panel side, a field electron emission film 15 formed thereon, and a fluorescence arrayed in an effective area of the anode panel AP so as to face the field electron emission film 15. The body layer 31 is constituted. In the effective area, such pixels are arranged on the order of hundreds of thousands to millions, for example.

  In addition, spacers 35 are arranged between the cathode panel CP and the anode panel AP at equal intervals in the effective region as an auxiliary means for maintaining a constant distance between the two panels. The shape of the spacer 35 is not limited to a cylindrical shape, and may be, for example, a spherical shape or a stripe-shaped partition wall (rib). In addition, the spacers 35 are not necessarily arranged at the four corners of the overlapping region of all the cathode electrodes, and may be arranged more sparsely or irregularly.

  In this display device, the voltage applied to the cathode electrode 11 is controlled in units of one pixel. As schematically shown in FIG. 2, the planar shape of the cathode electrode 11 is substantially rectangular, and each cathode electrode 11 is connected to the wiring 11A and a switching element (not shown) made of a transistor, for example. It is connected to the control circuit 40A. The anode electrode 33 is connected to the anode electrode control circuit 42. When a voltage equal to or higher than the threshold voltage is applied to each cathode electrode 11, electrons are emitted from the field electron emission film 15 based on the quantum tunnel effect by the electric field formed by the anode electrode 33, and the electrons are attracted to the anode electrode 33. And collides with the phosphor layer 31. The brightness is controlled by a voltage applied to the cathode electrode 11.

  Next, the display device is assembled. Specifically, in FIG. 1, the anode panel AP and the cathode panel CP are arranged so that the phosphor layer 31 and the field emission electrode face each other, and the anode panel AP and the cathode panel CP (more specifically, the substrate). 30 and the support 10) are joined to each other at the peripheral edge via the frame 34. At the time of joining, frit glass is applied to the joining part between the frame 34 and the anode panel AP and the joining part between the frame 34 and the cathode panel CP, and the anode panel AP, the cathode panel CP, and the frame 34 are bonded together. Then, after the frit glass is dried by preliminary baking, main baking is performed at about 450 ° C. for 10 to 30 minutes. After that, the space surrounded by the anode panel AP, the cathode panel CP, the frame body 34 and the frit glass is exhausted through the through hole and the tip tube, and the tip tube is heated when the pressure in the space reaches about 10 −4 Pa. Seal by melting. In this way, the space surrounded by the anode panel AP, the cathode panel CP, and the frame body 34 can be evacuated. Thereafter, wiring with necessary external circuits is performed to complete the display device.

  An example of a method for manufacturing the anode panel AP in the display device shown in FIG. 1 will be described below with reference to FIGS.

  First, a luminescent crystal particle composition is prepared. For that purpose, for example, a dispersant is dispersed in pure water, and stirring is performed at 3000 rpm for 1 minute using a homomixer. Next, the luminescent crystal particles are put into pure water in which a dispersant is dispersed, and stirred at 5000 rpm for 5 minutes using a homomixer. Thereafter, for example, polyvinyl alcohol and ammonium dichromate are added, and the mixture is sufficiently stirred and filtered.

  In the manufacture of the anode panel AP, a photosensitive coating 50 is formed (applied) on the entire surface of the substrate 30 made of glass, for example. Then, the photosensitive film 51 formed on the substrate 30 is exposed by ultraviolet rays emitted from an exposure light source (not shown) and passed through a hole 54 provided in the mask 53 to form a photosensitive region 51 ( (See (A) of FIG. 4). Thereafter, the photosensitive coating 50 is developed and selectively removed, and the remaining portion of the photosensitive coating (photosensitive coating after exposure and development) 52 is left on the substrate 30 (see FIG. 4B). Next, a carbon agent (carbon slurry) is applied to the entire surface, dried and fired, and then the remaining 52 of the photosensitive film and the carbon agent thereon are removed by a lift-off method, whereby carbon on the exposed substrate 30 is removed. A black matrix 32 made of an agent is formed, and at the same time, the remaining portion 52 of the photosensitive film is removed (see FIG. 4C). Thereafter, red, green, and blue phosphor layers 31 are formed on the exposed substrate 30 (see FIG. 4D). Specifically, a luminescent crystal particle composition prepared from each luminescent crystal particle (phosphor particle) is used. For example, a red photosensitive luminescent crystal particle composition (phosphor slurry) is applied to the entire surface. Apply, expose and develop, then apply green photosensitive luminescent crystal particle composition (phosphor slurry) over the entire surface, expose and develop, and further blue photosensitive luminescent crystal particle composition (Phosphor slurry) may be applied to the entire surface, exposed and developed. Thereafter, an anode electrode 33 made of an aluminum thin film having a thickness of about 0.07 μm is formed on the phosphor layer 31 and the black matrix 32 by sputtering. Each phosphor layer 31 can also be formed by a screen printing method or the like.

  The anode electrode may be an anode electrode of a type in which the effective area is covered with one sheet-like conductive material, or one or a plurality of field electron emission films, or an anode electrode corresponding to one or a plurality of pixels. An anode electrode of a type in which units are assembled may be used.

  One pixel may be constituted by a striped cathode electrode, a field electron emission film formed thereon, and a phosphor layer arranged in an effective area of the anode panel so as to face the field electron emission film. Good. In this case, the anode electrode also has a stripe shape. The projected image of the striped cathode electrode and the projected image of the striped anode electrode are orthogonal to each other. Electrons are emitted from the field electron emission film located in a region where the projection image of the anode electrode and the projection image of the cathode electrode overlap. The display device having such a configuration is driven by a so-called simple matrix method. That is, a relatively negative voltage is applied to the cathode electrode, and a relatively positive voltage is applied to the anode electrode. As a result, from the field electron emission film positioned in the anode electrode / cathode electrode overlapping region between the column-selected cathode electrode and the row-selected anode electrode (or the row-selected cathode electrode and the column-selected anode electrode). Electrons are selectively emitted into the vacuum space, and the electrons are attracted to the anode electrode and collide with the phosphor layer constituting the anode panel, thereby exciting and emitting the phosphor layer.

  In manufacturing the field emission electrode having such a structure, a cathode electrode forming conductive material layer made of, for example, a chromium (Cr) layer formed by sputtering, for example, is formed on a support 10 made of, for example, a glass substrate. The striped cathode electrode 11 may be formed on the support 10 instead of the rectangular cathode electrode by patterning the conductive material layer based on the well-known lithography technique and RIE method.

  Moreover, the order of plasma treatment, alignment treatment by an electric field, heat treatment, various plasma treatments, and the like can be arbitrarily set. The same applies to the following embodiments.

(4) Embodiment 4 (Tripolar Field Electron Emission Electrode / Field Electron Emission Display Device)
FIG. 5 shows a schematic partial end view of an example of the field emission electrode of the present embodiment, and FIG. 6 shows a schematic partial end view of the display device.
The field emission electrode includes a cathode electrode 11 formed on the support 10, an insulating layer 12 formed on the support 10 and the cathode electrode 11, a gate electrode 13 formed on the insulating layer 12, a gate electrode 13, and The opening formed in the insulating layer 12 (the first opening 14A formed in the gate electrode 13 and the second opening 14B formed in the insulating layer 12), and the second opening 14B The field electron emission film 15 is exposed at the bottom. The field electron emission film 15 is according to the second embodiment, and includes a matrix 21 and carbon nanotubes 20 embedded in the matrix 21 in a state in which a tip portion protrudes.

  The display device includes a cathode panel CP in which many field emission electrodes as described above are formed in an effective region, and an anode panel AP. The display device includes a plurality of pixels, and each pixel includes a plurality of field emission electrodes. The anode electrode 33 and the phosphor layer 31 are provided on the substrate 30 so as to face the field emission electrode. The anode electrode 33 has a sheet shape covering the effective area. The cathode panel CP and the anode panel AP are joined to each other at the peripheral edge via a frame 34. In the partial end view shown in FIG. 6, in the cathode panel CP, two openings 14A and 14B and one field electron emission film 15 are shown for each cathode electrode 11 for simplification of the drawing. However, the present invention is not limited to this, and the basic structure of the field emission electrode is as shown in FIG. Furthermore, a through-hole 36 for evacuation is provided in the ineffective region of the cathode panel CP, and a tip tube 37 that is sealed after evacuation is connected to the through-hole 36. However, FIG. 6 shows a completed state of the display device, and the illustrated tip tube 37 is already sealed. The illustration of the spacer is omitted.

  Since the structure of the anode panel AP can be the same as that of the anode panel AP described in the third embodiment, detailed description thereof is omitted.

  When performing display in this display device, a relative negative voltage is applied to the cathode electrode 11 from the cathode electrode control circuit 40, and a relative positive voltage is applied to the gate electrode 13 from the gate electrode control circuit 41. A positive voltage higher than that of the gate electrode 13 is applied to the anode electrode 33 from the anode electrode control circuit 42. When performing display in such a display device, for example, a scanning signal is input to the cathode electrode 11 from the cathode electrode control circuit 40, and a video signal is input to the gate electrode 13 from the gate electrode control circuit 41. Alternatively, a video signal may be input to the cathode electrode 11 from the cathode electrode control circuit 40 and a scanning signal may be input to the gate electrode 13 from the gate electrode control circuit 41. Electrons are emitted from the field electron emission film 15 based on the quantum tunnel effect due to an electric field generated when a voltage is applied between the cathode electrode 11 and the gate electrode 13, and the electrons are attracted to the anode electrode 33, so that the phosphor layer Collide with 31. As a result, the phosphor layer 31 is excited to emit light, and a desired image can be obtained.

  Hereinafter, the other embodiments of the field electron emission electrode and the field electron emission display device are the same as those already described in the third embodiment, and the other embodiments can be performed by using ordinary known techniques. Omitted.

Next, embodiments of the present invention will be described with reference to the drawings.
Test Examples 1 to 28
As the carbon nanotubes, SWNTs (single-walled carbon nanotubes) produced using the arc discharge device 60 (carbon nanotube production device) shown in FIG. 7 were purified by wet purification, and those having a purity of 80% or more were used.

  Here, the carbon nanotube production apparatus 60 will be described. The discharge chamber 63 can be depressurized by the rotary pump 61. The reduced pressure state of the discharge chamber 63 is measured by the vacuum gauge 62. A catalyst-containing graphite material 65 is installed on the anode 69 side of the discharge chamber 63, and a graphite material 64 is installed on the cathode 68 side. At the time of manufacturing the carbon nanotube, helium gas is introduced into the discharge chamber 63 from the He gas inlet 66, and a voltage is applied between the anode 69 and the cathode 68 by the DC power source 71, and a discharge is generated therebetween. Due to this discharge, the catalyst-containing graphite material 65 evaporates, and a part of the evaporated carbon is condensed in the gas phase and adheres to the inner wall of the discharge chamber 63 as soot. The generated soot is collected by a soot collecting port 67 provided in the lower part of the discharge chamber 63. A carbon nanotube is obtained by processing this soot by a known wet purification method.

  In accordance with the present invention, an ink for a field electron emission electrode comprising the carbon nanotube, a thermally decomposable metal compound, a dispersant 1, a dispersant 2, and a solvent was prepared. In this case, the carbon nanotube, the metal compound particles, the dispersant 1, the dispersant 2, and the solvent were sufficiently mixed at a predetermined concentration to prepare an ink. In mixing, the above mixture and zirconia beads were combined and placed in a paint shaker and mixed for 10 hours.

  As shown in Table 1 and Table 2 below, as the thermally decomposable metal compound, in Test Examples 1 to 21 and Test Examples 24 to 28, a mixture of tetrabutoxytin (TBT) and tributylindium (TBI) is used as a test example. In Test No. 22, a mixture of tetrabutoxytin (TBT) and trichloroindium (TCI) was used, and in Test Example 23, a mixture of tin tetrachloride (TCT: tetrachlorotin) and tributylindium (TBI) was used.

  Furthermore, the compounding quantity of the additive was shown here by mol% when a base material is set to 100. For example, in Test Example 1, 5 mol% of TBI was added to 100 mol of the base material TBT. The additive contains an element that functions as a dopant with respect to the metal element that constitutes the base material, and an oxide or halogenated compound in which the dopant element is bonded to the metal element by firing of the ink coating film. An oxide is formed. Specifically, in Test Examples 1 to 21 and Test Examples 24 to 28, TBT is a base material, TBI is an additive (indium is a dopant), and in Test Example 22, TBT is a base material and TCI is an additive (indium is an indium). Dopant). In Test Example 23, TCT is a base material, and TBI is an additive (indium is a dopant). In these test examples, ITO is generated by firing.

  Further, as a combination of the dispersant 1 and the dispersant 2, in Test Examples 1 to 23, a combination of docecil trimethyl ammonium chloride (DTMAC) and alkylbenzene sulfonic acid (ABS) was used. Among these, as the number of carbon atoms of the alkyl group of ABS, Test Example 1 is N = 3, Test Example 2 is N = 4, Test Examples 3 and 6 to 23 are N = 12, Test Example 4 is N = 20, Test In Example 5, N = 21. Further, in Test Examples 24 to 28, the dispersant 2 was fixed to ABS (N = 12), and as the dispersant 1, Test Example 24 was octadecylamine (ODA), Test Example 25 was dodecyldimethylamine (DDMA), and Test Example 26. Is dioctyldimethylammonium chloride (DODMAC), Test Example 27 is methyltrioctadecanyl ammonium chloride (MTOAC), and Test Example 28 is dimethyldioctadecanyl ammonium chloride (DMDOAC).

  As solvents, butyl acetate in Test Examples 1 to 6, 18 to 28, benzene in Test Example 7, toluene in Test Example 8, xylene in Test Example 9, acetone in Test Example 10, and methyl ethyl ketone (MEK) in Test Example 11 Test Example 12 is hexane, Test Example 13 is ethanol, Test Example 14 is isopropyl alcohol (IPA), Test Example 15 is dimethyl sulfoxide (DMSO), Test Example 16 is dimethylformamide (DMF), and Test Example 17 is tetrahydrofuran (THF). )It was used.

  In Tables 1 and 2 below, the concentration (parts by weight) of CNTs (carbon nanotubes) in the ink indicates the weight of the carbon nanotubes when the total weight of the ink is 100. Furthermore, in the ink according to Test Example 6, an appropriate amount of acetylacetone (Acac) was added as a chelating agent. In this case, the solvent concentration in the table is the total concentration with the chelating agent.

Next, the dispersibility and stability of the ink were evaluated using the obtained ink.
As an evaluation of dispersibility, the ink was observed with an optical microscope, and when there was no aggregation of 5 μm or more, ◯ when there was a small aggregate of 5 μm or more, Δ when there was a large aggregate of 5 μm or more . In addition, as the evaluation of stability, the ink was left to stand for 10 days, and the ink that did not precipitate or aggregate was evaluated as ◯, the aggregated as Δ, and the precipitated as ×.

  Further, a field electron emission film was formed on the electrode substrate using the ink, and the field electron emission characteristics (FE characteristics) were evaluated. The spray coating apparatus of FIG. 8 was used for ink application (formation of a field electron emission film) to the electrode substrate. The coating film thickness after drying by spray coating was 1 μm.

  The structure of the spray coating apparatus used and the ink coating method using this will be described with reference to FIG. An ink tank 72 is provided in the upper part, a nozzle 75 is provided in the lower part, a cock 72a is provided in the central part, and a flow rate control valve (not shown) is provided at a predetermined portion between the cock 72a and the nozzle 75, thereby constituting a coating apparatus main body. An air pipe 76 and a valve control air pipe 77 are connected to a portion of the main body immediately above the nozzle 75. The main body is movable back and forth in the direction of the arrow and perpendicular to the paper surface (movable in the X and Y directions).

  When applying ink, the field electron emission electrode substrate 73a is fixed to a predetermined position of the air chuck 74 by vacuum suction. The cock 72a is opened, pressurized air controlled to a predetermined pressure is supplied from the valve control air pipe 77 to the flow control valve, and pressurized air is supplied from the air pipe 76. As a result, the ink in the ink tank 72 is sprayed from the nozzle 75 onto the electrode substrate 73a. In this coating step, the electrode substrate 73a is movable in the X and Y directions. In FIG. 8, reference numeral 73 denotes a field electron emission electrode, and reference numeral 73b denotes an ink coating film.

This ink coating film was dried in the air at 200 ° C., baked at 470 ° C. for 30 minutes, and then surface-treated to project the carbon nanotubes on the surface, thus an electrode substrate for a field electron emission electrode (sample) Was made. The electrode substrate was cut into an appropriate size to obtain field electron emission electrodes as described below, and then the electrodes were evaluated.
In this example, the baking conditions for the coating film are optimized at 470 ° C. for 30 minutes. However, since the baking temperature is determined by the composition of the metal compound, the present invention is limited to the conditions in this example. It is not something.

  FIG. 9 is a schematic view showing an apparatus for evaluating a field electron emission electrode. 9, the reference numeral 78 denotes a glass pressing weight, 79 denotes an anode electrode (glass anode) obtained by applying a phosphor 79a on a glass substrate, 80 denotes a glass spacer (glass fiber), and 81 denotes the present invention. The cathode electrode 82 on which the field electron emission film 81a is applied is a power source and a voltage / current measuring instrument.

  A glass spacer 80 having a diameter of 1 mm was placed on the cathode electrode 81, and an anode electrode 79 was placed on the spacer so that the ITO film 79a faces the field electron emission film 81a. A weight 78 was placed on the anode electrode 79 to maintain the space. 5 kV was applied to the cathode electrode 81 in a vacuum (0.00001 Pa or less).

  The field electron emission characteristic (FE characteristic) was evaluated from the light emission state of the phosphor with voltage applied. That is, the light emitting area (15 × 15 mm) of the anode electrode 79 was photographed with a CCD camera and the light emitting area was calculated.

Comparative Example 1 [When no dispersant is used]
Without adding a dispersant, 0.05 parts by weight of carbon nanotubes were added to butyl acetate and dispersed by applying ultrasonic vibration. Thereafter, a mixture of TBT 100 mol% and TBI 5 mol% was added to obtain an ink of Comparative Example 1, and the above evaluation was performed.

Comparative Example 2 [when sodium dodecyl sulfate (SDS) is used]
SDS was dissolved in butyl acetate, 0.05 parts by weight of carbon nanotubes were added to the solution, and dispersed by applying ultrasonic vibration. Thereafter, a mixture of TBT 100 mol% and TBI 5 mol% was added to obtain the ink of Comparative Example 2, and the above evaluation was performed.

Comparative Example 3 [when polyoxyethylene-10-octylphenyl ether (Triton-X) is used]
Triton-X was used instead of the SDS of Comparative Example 2 as a dispersant, and the ink of Comparative Example 3 was prepared in the same manner as in Comparative Example 2 except for the above conditions, and the above evaluation was performed.

Comparative Example 4 [when octadecylamine (ODA) is used]
ODA was used instead of the SDS of Comparative Example 2 as a dispersant, and the ink of Comparative Example 4 was prepared in the same manner as in Comparative Example 2 except for the above conditions, and the above evaluation was performed.

Comparative Example 5 [When Docecil Trimethyl Ammonium Chloride (DTMAC) is Used]
DTMAC was dissolved in butyl acetate, 0.05 parts by weight of carbon nanotubes were added to the solution, and dispersed by applying ultrasonic vibration. Thereafter, a mixture of 100 mol% of TBT and 6 mol% of TBI was added to obtain an ink of Comparative Example 5, and the above evaluation was performed.

Comparative Example 6 [when dodecylbenzenesulfonic acid (ABS (N = 12)) is used]
The ink of Comparative Example 6 was prepared in the same manner as in Comparative Example 2 except that ABS (N = 12) was used instead of the SDS of Comparative Example 2 as a dispersant, and the above evaluation was performed.

  Tables 1 and 2 below summarize the evaluation of the components and compositions of the inks according to Comparative Examples 1 to 6 and Test Examples 1 to 28, and the evaluation results (FE characteristics) of field emission electrodes produced using this ink. It was.

  From the results of Tables 1 and 2, according to Test Examples 1 to 28, field electron emission electrode inks having excellent carbon nanotube dispersibility and high dispersion stability as compared with Comparative Examples 1 to 6 were obtained. In addition, by using the ink, a thin film can be uniformly formed without agglomeration of carbon nanotubes on the surface, and field electron emission characteristics are improved.

  In this example, TBT, TBI, TCI, TCT are used as the thermally decomposable organometallic compound, and butyl acetate, benzene, toluene, xylene, acetone, MEK, hexane, ethanol, IPA are used as the solvent. , DMSO, DMF, and THF were used as representatives, but the effects of the present invention are not limited to these, and excellent results can be obtained by using other thermally decomposable metal compounds and solvents. Can do.

It is a typical partial cross section figure of the field electron emission display apparatus of Embodiment 3 of this invention. It is a typical perspective view of one field electron emission film | membrane in the field electron emission display apparatus of Embodiment 3 of this invention. It is typical partial end views of a support etc. for explaining a manufacturing method of a field electron emission film in Embodiment 3 of the present invention. It is typical partial end views of the board | substrate etc. for demonstrating the manufacturing method of the anode panel in the field electron emission display apparatus of Embodiment 3 of this invention. It is typical partial end views of a support etc. for explaining the manufacturing method of the field electron emission element in Embodiment 4 of the present invention. It is a typical partial end view of the field electron emission display apparatus of Embodiment 4 of this invention. It is the schematic diagram which showed an example of the manufacturing apparatus of a carbon nanotube. It is the schematic of a spray coating apparatus. It is the schematic of the evaluation apparatus of a field electron emission electrode.

Explanation of symbols

CP ... cathode panel, AP ... anode panel, 10 ... support, 11 ... cathode electrode, 11A ... wiring, 12 ... insulating layer, 13 ... gate electrode, 14, 14A, 14B ... opening, 15 ... field electron emission film, DESCRIPTION OF SYMBOLS 20 ... Carbon nanotube, 21 ... Matrix, 30 ... Substrate, 32 ... Black matrix, 33 ... Anode electrode, 34 ... Frame, 35 ... Spacer, 36 ... Through-hole, 37 ... Tip tube, 40, 40A ... Cathode electrode control circuit , 41 ... Gate electrode control circuit, 42 ... Anode electrode control circuit, 50 ... Photosensitive coating, 51 ... Exposed portion of photosensitive coating, 52 ... Remaining portion of photosensitive coating, 53 ... Mask, 54 ... Hole, 61 ... Rotary Pump, 62 ... Vacuum gauge, 63 ... Radiation chamber, 64 ... Graphite material, 65 ... Catalyst-containing graphite material, 66 ... He gas inlet, 67 ... Soot recovery port, 68 ... Cathode, DESCRIPTION OF SYMBOLS 9 ... Anode, 70 ... Carbon nanotube manufacturing apparatus, 71 ... DC power supply, 72 ... Ink tank, 72a ... Cock, 73 ... Field electron emission electrode, 73a ... Electrode substrate, 73b ... Ink coating film, 74 ... Air chuck, 75 DESCRIPTION OF SYMBOLS ... Nozzle, 76 ... Air piping, 77 ... Valve control air piping, 78 ... Glass pressing weight, 79 ... Anode electrode, 79a ... ITO film, 80 ... Glass spacer, 81 ... Cathode electrode, 81a ... Field electron emission film, 82: Power source and voltage / current measuring device.

Claims (14)

0.005 to 5% by weight of a carbon nanotube structure, a thermally decomposable metal compound, a solvent, and a dispersant,
A field electron emission electrode ink, wherein the dispersant is a combination of an organic amine compound or an organic ammonium compound and an alkylbenzenesulfonic acid, an alkylsulfonic acid or a salt thereof.   2. The field electron emission ink according to claim 1, wherein the organic amine compound is a primary, secondary or tertiary amine having a linear or branched alkyl group having 4 or more carbon atoms.   The ink for a field electron emission electrode according to claim 1, wherein the organic ammonium compound has a linear or branched alkyl group having 4 or more carbon atoms.   The ink for a field electron emission electrode according to claim 1, wherein the alkylbenzenesulfonic acid and the alkyl group of the alkylsulfonic acid are linear or branched alkyl groups having 3 or more carbon atoms.   2. The field electron emission electrode ink according to claim 1, wherein a concentration of the organic amine compound or the organic ammonium compound in the ink in the dispersant is 0.001 to 1 wt%.   2. The field electron emission electrode ink according to claim 1, wherein the concentration of alkylbenzene sulfonic acid, alkyl sulfonic acid, or a salt thereof in the dispersant is 0.001 to 1 wt%.   2. The field electron emission electrode ink according to claim 1, wherein the thermally decomposable metal compound is an organometallic compound, a metal salt, or an organometallic salt compound.   2. The field electron emission electrode ink according to claim 1, wherein the thermally decomposable metal compound comprises a plurality of metals.   2. The field electron emission electrode ink according to claim 1, wherein the metal of the thermally decomposable metal compound is at least one additive metal selected from Sn, In and Sb.   2. The field electron emission electrode ink according to claim 1, wherein the concentration of the thermally decomposable metal compound in the ink is 0.1 to 50% by weight. A method of manufacturing a field electron emission film used for a field electron emission electrode,
0.005 to 5% by weight of a carbon nanotube structure, a thermally decomposable metal compound, a solvent, and a dispersant, wherein the dispersant is an organic amine compound or an organic ammonium compound, alkylbenzene sulfonic acid, alkyl sulfone A process for producing a field electron emission film comprising a step of applying an ink comprising an acid or a salt thereof on an electrode substrate. A method of manufacturing a bipolar field electron emission electrode comprising a cathode electrode and a field electron emission film sequentially formed on a support,
The manufacturing process of the field electron emission film includes 0.005 to 5% by weight of a carbon nanotube structure, a thermally decomposable metal compound, a solvent, and a dispersant, and the dispersant is an organic amine compound or organic An electric field comprising a step of applying an ink composed of a combination of an ammonium compound and an alkylbenzene sulfonic acid, an alkyl sulfonic acid or a salt thereof onto the cathode electrode, and a step of baking the coating film. Manufacturing method of electron emission electrode. A cathode electrode, an insulating layer and a gate electrode sequentially formed on the support, an opening formed in common with the insulating layer and the gate electrode, and a field electron emission film formed on at least the cathode electrode in the opening A method of manufacturing a tripolar field electron emission electrode comprising:
The manufacturing process of the field electron emission film includes 0.005 to 5% by weight of a carbon nanotube structure, a thermally decomposable metal compound, a solvent, and a dispersant, and the dispersant is an organic amine compound or organic An electric field comprising a step of applying an ink composed of a combination of an ammonium compound and an alkylbenzene sulfonic acid, an alkyl sulfonic acid or a salt thereof onto the cathode electrode, and a step of baking the coating film. Manufacturing method of electron emission electrode. A method of manufacturing a field electron emission display device in which a cathode panel having a plurality of field electron emission electrodes and an anode panel having a phosphor layer and an anode electrode are joined at the respective peripheral portions,
A method for manufacturing a field electron emission display device, wherein the field electron emission electrode is manufactured by the method according to claim 12 or 13.

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