KR100322457B1 - Oxide of electron emission material layer of cathode for electron tube and method for fabricating the same - Google Patents

Abstract

PURPOSE: An oxide of an electron emission material layer of a cathode for electron tube and a method for fabricating the same are provided to reduce the fabrication temperature of the oxide by using low energy and citrate to form the oxide of the electron emission material layer. CONSTITUTION: A mixture of carbonate and citric acid solution is heated under temperature of 100±20°C in order to fabricate metal-citrate. The crystalline powder as a complex of the metal-citrate is formed by recrystallizing the metal-citrate. An oxide of an electron emission material layer of a cathode for electron tube includes the crystalline powder as the complex of the metal-citrate. The metal-citrate is formed by using a metal material such as barium, strontium, and calcium.

Description

Oxide of electron-emitting material layer of cathode for electron tube and manufacturing method thereof

The present invention relates to an oxide of an electron emitting material layer of an electron tube cathode and a method of manufacturing the same, and more particularly, to easily form and decompose an oxide of an electron emitting material layer used for an electron tube cathode such as a TV with little energy. The present invention relates to an oxide of an electron-emitting material layer of a cathode for an electron tube having an advantage in terms of energy consumption by lowering an oxide production temperature by using an easy citrate, and a method of manufacturing the same.

Conventional electron emitting material layers are commonly known as carbonates, and a representative method for preparing carbonates is a coprecipitation method of obtaining solid precipitates by carbonate ions from a homogeneous mixed solution of soluble constituents. It is a method obtained by adding sodium carbonate to salt solutions such as hydrochloric acid and nitric acid, in which mol and calcium are dissolved in a constant molar ratio to form and precipitate a complex carbonate, followed by filtration and drying.

However, such a coprecipitation method has a problem that it is difficult to set the precipitation conditions due to the high possibility of fractional precipitation, there is a possibility of contamination, difficult to mass production and continuous operation, as described above in the method of making the raw material of the electron emitting material In analyzing in detail what is common in industrial applications, it can be pointed out that the key issues are manufacturing costs and product quality issues, which can be summarized as an ideal industrial method. . That is, the former manufacturing cost factor is that these should be minimized due to the raw material price, energy cost, and processing cost, and in the latter, the quality of the product should be guaranteed. Not only should the recovery rate of the products produced be large, but also the defective products should be secured so that the reliability of the finished product can be secured.

In view of this point, an object of the present invention is to provide an electron-emitting material of a cathode for an electron tube and a method of manufacturing the same, which can lower the cost and facilitate the utilization of the finished product under quality assurance.

Characteristic of the oxide of the electron-emitting material layer of the cathode for the electron tube according to the present invention for achieving the above object, by mixing the carbonate of alkali earth metals such as barium, strontium, calcium with citric acid solution to make the citric acid salt and the citric acid It is composed of crystalline fine powder which is a complex of metal-citrate obtained from a complex salt.

Characteristic of the method for producing an oxide of the electron-emitting material layer of the cathode for an electron tube according to the present invention for achieving the above object is a mixed solution by mixing carbonates of alkali earth metals such as barium, strontium, calcium and the like with citric acid solution A first step of forming a mixture, a second step of forming a complex salt of metal-citric acid by heating the mixed solution at a low temperature, and a precipitate product of a uniformly mixed metal-citrate salt by recrystallizing the complex salt of metal-citric acid (crystalline In the third step of obtaining a fine powder).

Hereinafter, a preferred embodiment of the oxide of the electron-emitting material layer of the cathode for an electron tube according to the present invention and a method for producing the same will be described in detail.

However, although this embodiment is described by a specific embodiment to help understanding of the present invention, the present invention is not limited to the following embodiments, and there may be many changes and modifications within the claims.

First, the samples to be prepared as the first step are prepared with barium carbonate (BaCO 3), strontium carbonate (SrCO 3), calcium carbonate (CaCO 3) and citric acid (CaCO 3) with a purity of 99.9%. After drying completely in an oven maintained at 110 ° C., the weighed carbonate is mixed with a solution weighed strictly and citric acid is dissolved in a minimum of deionized water, and then the metal is prepared from the mixed sample prepared in the first step as the second and third steps. The formation of citrate can be accomplished by their heating and cooling operations, that is, a mixture of carbonates and citric acid solutions of the metallic elements of each alkaline metal is dissolved completely with a slight heating (about 120 ° C) on a hotplate and then This is accomplished by repeating the process of simmering and cooling to obtain a complex precipitate consisting of a complex salt of metal-citric acid.

Referring to the overall manufacturing process of the second step and the third step, the metal carbonates and the citric acid mixed solution, which is the raw material mixture of the first step as described above, are dissolved and cleared with the generation of carbonic acid gas under heating in the second step. In the temperature range that maintains this clear solution as it turns into a solution, it can be seen that it is an ionic grain because of its high electrical conductivity, which forms a complex salt of metal-citric acid, which is a perfect mixture of the components. The complex salt solution of the metal-citric acid is precipitated again by the temperature drop in the third process, and finally the precipitated product of the metal-citric acid present in the reaction vessel is a crystalline fine powder which is a complex of metal-citrate mixed with component elements. It will be.

Examining the suitability of the oxide of the electron-emitting material layer of the cathode for an electron tube according to the present invention as described above and the material prepared by the method of manufacturing the same, the requirements for compatibility of the electron-emitting material layer as a raw material is a composite oxide of interest by firing It is desirable to obtain only single phase crystals, and to be as low as possible at the firing temperature, and to achieve this, the chemical composition of the components must be constant and the mixing needs to be uniform. Therefore, the degree of mixing of the non-combustion decomposition products produced by the present method As a result of diffraction of infrared and X-rays on the crystalline derivatives of the metal-citrates, the transmission graph according to the infrared wavelength by infrared absorption analysis of FIG. 1 and the X-ray diffraction analysis results of FIG. Likewise, the crystalline fine powder of the metal-citrate can confirm that the mixing of the components is completely uniform. It is.

According to the oxide of the electron-emitting material layer of the cathode for an electron tube according to the present invention as described above and the production method thereof, the conventional production method can be obtained by a much simpler process than the coprecipitation method and the manufacturing conditions are also difficult. In addition, since the decomposition of citrate occurs at a lower temperature than carbonate, such a change from citrate to oxide is performed at a low temperature so that the formation temperature of the electron emitting material layer by the conventional process can be lowered from 950 ° C to about 300 ° C. In addition, it can be very useful in terms of energy consumption when citrate is substituted for carbonate as a raw material for forming an electron emitting material layer, and this method can also be uniformly formed by formation of a metal-citric acid complex salt with only a little heat treatment. You can get a mixture of intermediates There is a usefulness that enables the production of various complex oxides of composition.

1 is an infrared spectrum diagram of a metal-citrate obtained after the reaction according to the present invention.

2 is an X-ray diffraction pattern diagram of a metal-citrate obtained after the reaction according to the present invention.

Claims (3)

The metal carbonate is mixed with a citric acid solution and heated to a temperature of 100 ± 20 ° C. to prepare a metal-citrate, and the electrons of the negative electrode for an electron tube containing crystalline fine powder, which is a complex of metal-citrate prepared by recrystallization of the metal-citrate Oxide of the emissive material layer. The method of claim 1, The metal citrate is an oxide of the electron-emitting material layer of the cathode for an electron tube, characterized in that the metal material using barium, strontium, calcium of alkaline earth metals. A first step of mixing a metal carbonate with a citric acid solution to form a mixed solution, A second step of heating the mixed solution to a temperature of 100 ± 20 ° C. to form a metal-citrate, And a third step of obtaining a crystalline fine powder, which is a composite precipitate of a metal-citrate, by recrystallization from the metal-citrate.