JPS6057177B2 - Cathode ray tube manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a cathode ray tube, and particularly to a baking process.

A cathode ray tube, particularly a color picture tube, displays a predetermined pattern of images by colliding an electron beam with the tip of the inner surface of the face plate that makes up the bulb, and is manufactured as follows. .

That is, a mixture of silicon native particles and a photosensitive binder (eg, polyvinyl alcohol and ammonium dichromate) is applied to the panel to form a fluorescent film. Then,
After applying an acrylic emulsion to the surface of this fluorescent film, a metal back is applied. Next, this panel is heat-treated at a high temperature in a furnace in order to decompose organic substances such as the polymer mixed with the silicon particles and the acrylic polymer used to apply the metal back. This is called panel baking. After passing through such steps, the panel and the funnel-shaped funnel are joined via solder glass, and in this state, heat treatment is performed at a high temperature in a furnace to solidify the solder glass. Thereby, the panel and the funnel can be integrated in a sealed state to form a valve. The above heat treatment is called frit baking. Furthermore, after attaching an electron gun to the neck of the valve, it is subjected to high temperature treatment. In this step, the organic matter remaining in the fluorescent film is decomposed without being decomposed by panel baking or frit baking, and the gas inside the bulb is exhausted to create a high vacuum inside the bulb. As is clear from the above processes, the conventional manufacturing method for color picture tubes requires a baking process three times, which consumes a large amount of energy, and also has the disadvantage that it cannot improve the mass productivity of color picture tubes. There is.

Therefore, an object of the present invention is to reduce the baking process to two by performing panel baking and frit baking almost simultaneously during the production of color picture tubes, thereby reducing energy consumption and facilitating the mass production of color picture tubes. This will be explained in detail below using examples.

FIG. 1 is a simplified structural diagram showing a method for manufacturing a cathode ray tube according to the present invention, and particularly shows the case where the present invention is applied to a color picture tube.

In the figure, reference numeral 1 denotes a panel on which a fluorescent film, an acrylic film, and a metal back are sequentially applied on the inner surface, and a shadow mask is attached, and the panel has not yet been baked. In the present invention, a panel that has not been subjected to such panel baking is bonded to the opening of the funnel 3 via the solder glass 2, and is baked in a furnace. Baking in a closed container will not decompose the organic matter in the phosphor film enough, leaving a lot of organic residue in the phosphor film, and the lead oxide, which is a component of solder glass 2, will be reduced. The fusion will be incomplete. This is because the gas produced by the decomposition of the organic matter remains in the bulb, and at the same time there is a lack of oxygen, which prevents the decomposition of the organic matter and reduces the solder glass 2. Therefore, in order to solve the above-mentioned problems, in the present invention, a vibrator I5 is protruded from the container 4 as shown in the figure, this vibrator 5 is inserted from the neck 6 of the funnel 3, and the vibrator I5 is inserted into the container 4. A substance 7 that generates oxygen through thermal decomposition is contained in the container, and the entire container is baked in this state.

Note that 8 is a filter. According to this method, oxygen is generated from the thermally decomposed substance 7 during baking and is sent into the bulb, so that the organic matter in the fluorescent film is sufficiently decomposed and the lead in the solder glass 2 is removed. is not reduced and the fusion becomes complete. The fine powder of the substance 7 generated during thermal decomposition is cut off by the filter 8 and there is no fear of it flowing into the valve. Based on the above opinion, the inventor conducted baking according to the following specifications.

first. As shown in FIG. 1, a vibrator 5 of a container 4 was passed through a 20-inch panel 1 and a funnel 3 joined together with a solder glass 2 interposed therebetween. In this case, container 4
40 grams of potassium permanganate were used as the pyrolysis material 7 contained in the pyrolyzate. Then, a filter 8 made of quartz glass wool was placed at the tip of the vibrator 5, and the assembled product was placed in a furnace and the temperature was lowered from 20°C to 430°C at a cooling rate of 8°C/min. It was held for 60 minutes. Then 50 at a rate of 3°C/Mjn
The temperature was lowered to ℃. As a result, the decomposition of the organic matter and the fusion by the solder glass were completely carried out, and the characteristics of the cathode ray tube were almost the same as those of conventional ones. The reason why such good characteristics can be obtained is as follows. That is, under the heating conditions of the above method, until the temperature approaches 200°C, the organic matter in the fluorescent film thermally decomposes and generates gas while consuming oxygen in the bulb, but at 200°C,
A thermal decomposition reaction as shown in equation (1) occurs for substance 7! ．．
! Ru. That is, 3 liters of oxygen is generated from the substance 7 and sent into the valve, and this oxygen is consumed in thermal decomposition of organic matter at 200° C. or higher, thereby achieving the above effect.

In this case, when the substance 7 is thermally decomposed, potassium permanganate powder scatters and tries to flow into the valve through the vibrator 5, but the outflow of this potassium permanganate powder is blocked by a filter 8 made of quartz glass wool. be done. If potassium permanganate powder were to flow into the bulb, it would be very difficult to remove it from the bulb, and it would also cause sparks during operation of the cathode ray tube.
However, according to the present invention, there is no such fear. Next, the inventor connected two containers 41 and 42 to the vibrator 5 as shown in FIG.
0 grams of potassium permanganate 71 and 19 grams of copper dioxide 72 were stored and baking was performed in the same manner as above.

I was able to get the result. This is due to the following reasons. That is, when the decomposition of potassium permanganate 71 is completed and the temperature reaches 350°C, the thermal decomposition reaction shown in equation (2) occurs on copper dioxide 72. 3 that occurred at this time
The liter of oxygen flows into the valve and is refluxed inside the valve, and this oxygen is used for thermal decomposition of organic matter at 350° C. or higher, so that oxygen can be used effectively and good effects can be obtained.

Here, in this example, potassium permanganate and copper dioxide are used as substances that generate oxygen through thermal decomposition, but the present invention is not limited thereto, and noble metal oxides with a small ionization tendency are used. (Hg, Ag oxides), metal peroxides (BaO2), highly oxidized metal oxides (MnO2, PbO2), alkali metal oxylates (nitrates, perchlorates, chlorates), etc. may also be used.

The thermal decomposition temperature of the material used at this time is 2000C.
It is better to use the above. The reason for this is that the thermal decomposition of polyvinyl alcohol and acrylic filming agents becomes more intense at around 200°C, so at around this temperature the oxygen that was already present in the tube is first consumed by the thermal decomposition of some organic matter, and then This is because oxygen can be used effectively by raising the temperature to a high temperature, generating oxygen from the substance 7 through thermal decomposition, discharging the decomposed gas in the tube, and using this oxygen to thermally decompose the remaining organic matter. Although this embodiment has been described as using one or two types of substances 7, the present invention is not limited thereto, and two or more types of substances having different thermal decomposition temperatures may be used.

In this way, the oxygen utilization efficiency can be further improved. Next, the amount of oxygen required to decompose the organic matter present in the phosphor film can be determined by using the frit baking process twice without using the panel baking process. From the experimental results, a volume twice as large as the internal volume of the bulb formed by combining the panel 1 and the funnel 3 is sufficient.

From this volume, the amount of the substance 7 that generates oxygen through thermal decomposition can be calculated. As a result of calculating the amount of the substance 7 using this method, it was found that 2 liters is sufficient for the smallest 10-inch color cathode ray tube. As explained above, according to the method of manufacturing a cathode ray tube according to the present invention, organic matter in the fluorescent film is decomposed and the panel 1
and funnel 3 can be simultaneously fused at high temperatures, thereby eliminating the need for panel baking for the purpose of decomposing organic matter, reducing the energy and baking process to 2/3 of the conventional baking process. It has great effects.

[Brief explanation of the drawing]

1 and 2 are simplified configuration diagrams for explaining the method of manufacturing a cathode ray tube according to the present invention. 1...Panel, 2...Solder glass,
3...Funnel, 4...Container, 5.
...Vibe, 6...Neck part, 7...
...Pyrolysis substance, 8...Filter.

Claims (1)

[Claims] 1. A panel having at least a fluorescent film coated on its inner surface,
It is placed in the opening of the funnel via solder glass, and baked in this assembled state, and a substance that generates oxygen through thermal decomposition is heated in the baking, so that the oxygen generated from the substance is released from the neck opening of the funnel. A method for manufacturing a cathode ray tube, characterized in that the flow is caused to flow at least to decompose organic matter in the phosphor film and to fuse the panel and funnel with solder glass. 2. Claim 1 in which a noble metal oxide or metal peroxide with a small ionization tendency, a metal oxide in a highly oxidized state, or an alkali metal oxyacid salt is used as the substance that generates oxygen through thermal decomposition. A method for manufacturing a cathode ray tube as described in . 3. The method of manufacturing a cathode ray tube according to claim 1, wherein a plurality of substances having different thermal decomposition temperatures are used as the substance that generates oxygen through thermal decomposition. 4 The amount of substances that generate oxygen through thermal decomposition is the amount of cathode ray tube 1
2. The method of manufacturing a cathode ray tube according to claim 1, wherein the amount of oxygen generated is 2 to 50 liters depending on the decomposition temperature of the pyrolytic material used. 5 A panel having at least a fluorescent film coated on its inner surface,
It is placed in the opening of the funnel via solder glass, and baked in this assembled state, and a substance that generates oxygen through thermal decomposition is heated in the baking, so that the oxygen generated from the substance is released from the neck opening of the funnel. In a method for manufacturing a cathode ray tube in which oxygen is introduced into the phosphor film to decompose organic matter in the phosphor film and fuse the panel and funnel using solder glass, when oxygen is allowed to flow in through the neck opening, the neck opening is 1. A method of manufacturing a cathode ray tube, characterized in that a pipe is used which extends to the vicinity of the fluorescent film through the tube and has a built-in filter for cutting off fine powder of pyrolytic substances.