TWI258789B - Carbon nanotube suspension - Google Patents

Abstract

A carbon nanotube suspension is provided, which utilizes water as base solvent with addition of solutes of dispersion agent, stabilizer, film-forming agent, viscofier, etc. and nanocarbon tube. The base solvent and solute are put together to form low viscosity aqueous solution within which carbon nanotube is suspended to form carbon nanotube suspension. The disclosed carbon nanotube suspension can be used as raw material of electron emission source for field emission display in which carbon nanotube is deployed in a manner of coating suspension.

Description

1258789 V. INSTRUCTION OF THE INVENTION [Technical Field] The present invention relates to a naphtha, a tube immersed in a specific eight-disgusting core liquid, especially a suspension of nano carbon, which can be proud of 2, 7, The carbon nanotube suspension formed in the sap can be used as the electron emission source for the field emission display. [Previous technology] Near: New amps are not EmiSSi〇n DiSPlay, FED) is flat: display -, • The reason is that it has auto-luminescence = 4 source, compared with lcd, in addition to better reaction speed, viewing angle range, low power consumption, and the bean's smuth, (residual shirt) operating temperature range is wider, etc. Advantages, f 1 image quality is very similar to the traditional cathode ray tube 33 is not, and its volume is much lighter and thinner than the cathode ray tube, compared with the liquid crystal display (LCD) viewing angle range is small, the reaction speed is insufficient Shortcomings such as insufficient shell size (especially for large size), and the high power consumption of the plasma display (PDP), high heat generation, unsuitable for small-sized panels and poor overall black performance, etc. One to overcome, the field emission Shows a liquid crystal display device becomes substituted and plasma display ^ rising star on the matter as it may be said of. Moreover, due to the rapid development of nanotechnology in recent years, the application of nanomaterials to field emission displays will further promote its development into mature products. The first figure shows a cross-sectional view of a typical three-pole structure field emission display. Its structure mainly consists of anode plate (1 〇) and cathode plate (2 〇), anode plate (10) and cathode plate (20). ) is provided with a supporter ( spacer)

Page 6 1258789 V. Description of the Invention (2) (1 4 ), provided as the gap between the anode plate (丨〇) and the cathode plate (2 (8), and as the anode plate (; 10) and cathode plate (2 〇 Between the support, the anode plate U 0 ) comprises an anode substrate (丨丨), an anode conductive layer (12) and a phosphor layer (13); and the cathode plate ( 2)) comprising a cathode substrate (2 1 ), a cathode conductive layer (2 2 ), an electron emission source layer (23) dielectric layer (24) and a gate layer (25); wherein the gate The layer (25) j is provided with a potential difference to induce the electron emission of the electron emission source layer (23), and the high voltage supplied by the anode conductive layer U2) to provide an acceleration of the electron beam, so that the electron has sufficient kinetic energy to hit ( The phosphor powder layer (13) on the anode plate (1〇) is excited to emit light. After the invention of the carbon nanotubes, since the characteristics of the carbon nanotubes are in line with the requirements of the field display, the field emission display has recently adopted the carbon nanotubes as the electron emission source of the % emission display. The carbon nanotubes are disposed on the cathode plate of the field emission display to form an electron emission source (23), and the conventional ones use the screen printing technology, which is used by the screen printing technology. The carbon nanotube coating is a high viscosity mixed liquid with a viscosity exceeding 丨Q 〇〇cps, and the formed electron emission source layer (23) has a surface which is difficult to be flattened, so that the electron emission source layer in the same cathode unit (2) 3) The gap between the corresponding gate layer (25) is difficult to achieve, and the electric field strength between them is not uniform, and the electron emission source layer (23) cannot uniformly emit electrons at each position, that is, the gap is relatively small. In small places, the electric field strength is larger, and more electrons are emitted. In addition, the mixed liquid used in screen printing technology is extremely difficult to disperse due to its extremely high viscosity, and it must rely on mechanical or physical properties. Dispersion technology is dispersed, even if it is still difficult to control the carbon nanotubes in the electron emission source layer (23)

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Page 7 V. Invention Description (3y ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ _ The cost is consistent, that is, Gong Tai > shot unevenly. These two factors: even 2 difference: will also make the electronic element of the fire The hairpin of the powder layer (13) will cause the same anode single-anode unit to emit light; im hook, under ideal conditions, the carbon nanotube electron emission source, :: single screen printing; In the case of darkness, that is, lowering ^蚩^ = 兀, there will be a bright mixed liquid, although the viscosity is high, but the complex::=σα $. Moreover, this high viscosity when the ratio of the fixing material, such as broken Insufficient department, it is necessary to add phase tube, adding more complexity in the process: field powder 4, can fully fix the carbon content of the nanometer] The main suspension of the Ming is the other way to make the cloth, the other is lower, no need to re-optimize According to another aspect of the present invention, the present invention is a low-viscosity film layer thickness for the purpose of the above-mentioned purpose, for the purpose of field development, for the purpose of chemical use of high viscosity, liquid, uniform, that is, the display of carbon nanotubes That is, the action is a mechanical or mixed liquid Providing an electron emission source of a carbon nanotube device, which is easy to be applied to provide a nano carbon tube to an excellent nano carbon tube physical device, and provides a carbon nanotube method for conducting a carbon nanotube 'Eso can make the surface of the film'. The present invention utilizes a water-based solvent, the film agent and the addition of 1 (4) of the bulk and the nanoscopic barrier suspension, the raw material, the suspension thereof, and the dispersed dispersion of the suspension, The flatness of the layout is added to the dispersion 'the base 1258789

The base solvent and the solute form a low viscosity aqueous solution, and the nano carbon tube suspension of the present invention is formed in too + π a Sll e w . [Embodiment] 4 ^ :? Each, mainly reveals a composition of the nanocarbon tube: : ΐ 为 as the base solvent, and dissolved in the solute such as dispersant, stabilizer, film formation ~ two:: agent, forming a low viscosity water: liquid ' S The immersed carbon nanotubes with a length of 1 or less are placed in the aqueous solution:: and: the composition of the solute and the carbon nanotubes of the -carbon nanotube suspension are as follows: 1. Nanocarbon tube: 5 % to 20%. 2. Film-forming agent: 5% to 20%, which may be sodium aluminum sulfate, decane coupling agent, colloidal oxygen or tetraethoxy decane (Ding 61:1^£1:1^1〇1'1:11) One or more of 〇8丨1丨(:^1:6, TE 0 S) makes the suspension easy to adhere to the glass substrate of the field emission display, and makes the suspension have better film forming properties. ·Tackifier: 1% to 5%, one of polyvinyl alcohol (PVA), polyvinyl acenaphthyl ketone (PVP), methyl cellulose, ethyl cellulose, sodium polyacrylate, polypropylene ammonium The viscosity of the suspension can be increased in accordance with the process requirements of the 砀 emission display, and the film thickness can be easily controlled. 4. Stabilizer: 〇·5 % to 5%, one of gas water, potassium hydroxide and sodium hydroxide. Increase the shelf life of the suspension 'to allow the carbon nanotubes to have ample time to disperse. 5 · Dispersant · · 1% to 1%, ethylene glycol and sodium alkyl sulfonate. Promote carbon nanotubes Dispersion in suspension

9th f 1258789 V. Description of invention (5) ---............-............ ^~~ 6 ·/ 肖泡Μ · 1 乂 to 1 Q %, poly Propylene propylene glycol. Eliminate the beads produced when the liquid is mixed. The preferred composition and preparation method of the carbon nanotube suspension of the present invention is as shown in the second figure, and includes: γ step 50, with water as the main constituent base solvent, in the composition and mixing process, the foundation is The total mass of the solvent is used as the basis for the ratio and is calculated. Step 51' A pre-configured 5% sodium organoalkyl sulfonate (dispersant) and 5% defoamer are mixed in the base solvent. Step 52' is added to a 1% carbon nanotube. In the step, the preliminary mixture obtained by mixing the above steps 5 〇 52 52 is subjected to shaking stirring using an ultrasonic vibration technique. This shaking and stirring time is preferably 3 hours. Step 5 4 ' Add 1% ammonia water (stabilizer) to the composition mixture after shaking and stirring in step 5 3, and then stir. Step 5 5, adding 5% sodium aluminum sulfate (film former), 1% decane coupling agent (film former), 2 · 8 % ρ ν Α (tackifier) and 2% ethylene glycol (Dispersant). In step 5, the mixture of the components obtained in the above steps 5 〇 5 5 5 is mixed, and finally a low viscosity carbon nanotube suspension is formed by a 50 Omesh mesh screening process. By using the above composition to be mixed at appropriate mass percentages, the obtained low-viscosity carbon nanotube suspension has a viscosity of only 24 cps and a solid content of 14%, which is much lower than the currently known carbon nanotube coating. Viscosity, so that it can be coated

Page 10 1258789 V. Description of the invention (6) The layout of the nanometer probe coagulation, but it is not possible to obtain the solution in the suspension of the cathode substrate on the surface of the cathode substrate The composition of the other auxiliary solutions should be referred to the manufacturer of the low-viscosity source. It is not only chemically developed to extremely high-grade, but also excellent in the formation of electrons and processes on the composition. The dissolved electron emission source needs to be added. Any carbon tube deposition dense material may be liquid to increase the dispersion of the carbon nanotube suspension method in the three layers of the solution, so that the rice carbon tube splitting effect constitutes a liquid nano-layer of a low-viscosity emission source; Therefore, the solidity of the material will not be simplified, and the liquid can be floated in the flatness and uniformity of the suspension in the flatness of the nano-carbon process, the carbon tube, directly in the present invention. If the glass is thinner and can be used in the object d, the polar substrate is good, and the carbon nanotubes with dispersing agent are not applied to the field emission, and the floating liquid can be directly matched with the true connection. Fixing at the cathode base low viscosity Carbon nanotube powder, so that the relative release 'thereby making step was dissolved in a solution square reference describes the use of the present electron-emitting surface is formed

= The configuration of the carbon nanotube suspension of Ming Nylon is mainly applied to the field emission and is used for the layout of the electron emission source. Please refer to the third figure, which mainly incorporates the negative photoresist and combines the photolithography process and the etching process. To make, package two i = layer production, totemization definition of the surface of the cathode substrate electron emission zone system is not a slave of the electron emission source layer fabrication and vacuum sintering fixation. The lower step is a typical application of the present invention: (a) A cathode substrate 6 is provided as shown in Fig. 3a. (b) using a photolithography process in conjunction with the totemization technique to form a removable photoresist layer 7 on the counter-surface of the cathode base, and by the totemization technique,

Page 11 1258789 V. The invention says that the sun and the moon (7) plan to have a plurality of discontinuous electron-emitting regions 8, as shown in Figure 3b (4), and then combine the development process with an etching process to remove the photoresist layer. The source Luguang is vacuum sintered to form an electron emission source layer 9 fixed to the surface of the cathode substrate 6, as shown in Fig. 3d. The electron emission source layer 4 made by the t method has an excellent surface flatness and the distribution of the carbon nanotubes is also extremely uniform, so that the electron beam 1 is extremely uniform, and the field emission display is The improvement in quality has positive benefits. The carbon nanotube suspension provided by the present invention, the above examples are used to explain and not to unduly limit the scope of the patent application of the present invention, and other equivalent transformations not described herein shall belong to the present invention. Within the scope of the patent. «

Page 12 1258789 Brief Description of the Diagram First: A cross-sectional view of a typical field emission display. Fig. 2 is a flow chart showing the manufacturing steps of the composition of the composition of the carbon nanotube suspension of the present invention. Fig. 3 is a flow chart showing the fabrication of an embodiment of the method for producing an electron emission source using the solution of the present invention. Main component representative symbol description Step 5 0 Step 5 2 Step 54 Step 5 6 Photoresist layer 7 Electron emission source layer 9 Step 5 1 Step 5 3 Step 5 5 Cathode substrate 6 Electron emission region 8

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Claims (1)

1258789 VI. Patent Application Range 1. A carbon nanotube suspension consisting of: water, a base solvent; a plurality of carbon nanotubes: 5% to 20%; a film former: 5% to 20% Adhesive: 1% to 5%; Stabilizer··0.5% to 5%; Dispersant: 1% to 10%; Defoamer: 1% to 10%. 2. The carbon nanotube suspension according to claim 1, wherein the carbon nanotube has a length of less than 1 // m. 3. The carbon nanotube suspension of claim 1, wherein the dispersing agent is ethylene glycol or an organic alkyl sulfonate. 4. The carbon nanotube suspension according to claim 1, wherein the antifoaming agent is polycyclopropene propylene glycol. 5. The carbon nanotube suspension according to claim 1, wherein the film forming agent is sodium aluminum sulfate, a decane coupling agent, a colloidal oxygen or a tetraethoxy decane (TEOS). One or more. 6. The carbon nanotube suspension according to claim 1, wherein the tackifier is polyvinyl alcohol (PVA), polyvinyl pentoxide (PVP), sulfhydryl cellulose, and B. 7. The sodium carbon nanotube suspension according to claim 1, wherein the stabilizer is sodium hydroxide, potassium hydroxide or ammonia water, etc. One. 8. The method for preparing a carbon nanotube suspension comprises the following steps: Page 14 1258789 VI. Application for specific w a. Water-based solvent, uniformly mix 1 to 10% dispersant and 1% to 10% defoamer; b. Add 5% to 20% The carbon nanotubes; c. The mixture obtained in the steps a and b is subjected to a stirring process for a period of shaking and stirring; d. adding 0.5% to 5% of the stabilizer, and then stirring; e. adding 5% Up to 20% of the film-forming agent, 1% to 5% of the tackifier, stirring for a while; f · Yishi. 9. The method for preparing a carbon nanotube suspension according to claim 8, wherein the length of the carbon nanotube is less than 1 // m. A method of preparing a carbon nanotube suspension according to claim 8 wherein the dispersing agent is ethylene glycol or an organic alkyl sulfonate. 1 1. The method for preparing a carbon nanotube suspension according to claim 8, wherein the antifoaming agent is polycyclopropene propylene glycol. 1 2. The method for preparing a carbon nanotube suspension according to claim 8, wherein the film forming agent is sodium aluminum sulfate, a decane coupling agent, a colloidal oxygen or a tetraethoxy zebra ( TEOS) One or more of them. 1 . The carbon nanotube suspension according to claim 8 , wherein the tackifier is polyvinyl alcohol (PVA), polyvinyl pentoxide (PVP), methyl cellulose, Ethyl cellulose, sodium polyacrylate, and ammonium acrylate. The method for preparing a carbon nanotube suspension according to claim 8 wherein the stabilizer is sodium hydroxide or potassium hydroxide. Or ammonia water, etc. Page 15 1258789 VI. Patent Application _ —— 〇 1 5. The method for suspending a carbon nanotube suspension as described in claim 8 wherein the agitation procedure is performed by ultrasonic stirring. The method of preparing a carbon nanotube suspension composition according to claim 8, wherein the screen is 50,000 m e s h. « Page 16