JPH01211830A - Manufacture of cathode-ray tube - Google Patents

Abstract

PURPOSE:To obtain a highly durable coating by applying a solution, which is prepared by mixing the fine grains of predetermined transparent and electrically conductive oxides and mixture thereof into alcoholic solution with predetermined composition, onto the panel surface of a cathode-ray tube, then carrying out heat treatment thereof at a specific temperature. CONSTITUTION:An antistatic coating 2 formed on the panel surface of a cathode-ray tube 1 is formed in the following way. Fine transparent grains having electrical conductivity e.g., (a) SnO2, (b) In2O3, (c) Sb2O3, and mixture thereof, i.e. fine grains of any one of (a), (b), (a+b), (a+b+c), (a+c) and (b+c) are sufficiently well mixed into an alcoholic solution of alkyl silicate Si-(OR), (R: alkyl group) to produce a solution. While the cathode ray tube 1 is rotated at a speed of 100rpm with the panel surface upward, this solution is dropped on the panel surface and when the solution has been spread all over the surface, the rotating speed is increased to 500rpm to coat the surface thinly and uniformly with the solution, then, after heating and drying thereof at a temperature less than 200 deg.C, e.g., at 105 deg.C, for about 10min, burning is effected at 160 deg.C for 30min to form the antistatic coating 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing cathode ray tubes, and in particular,
The present invention relates to a method for forming an antistatic film on the surface of a panel.

[Conventional technology]

When color cathode ray tubes and display cathode ray tubes are turned on or off, the inner surface of the cathode ray tube panel is hit by an electron beam that causes the phosphor to emit light.
(negative) high potential is formed or disappears suddenly. At that time, an electric charge is generated on the outer surface of the panel to counteract the internal high voltage, and the charged static electricity remains unattenuated and may cause discomfort to the human body.
If you come into contact with the surface of a cathode ray tube, you will receive an electric shock as the accumulated charge is discharged through your body. In addition, oppositely charged dust, dirt, contaminants, etc. in the air are attracted to and adhere to the panel, causing deterioration in the brightness of the cathode ray tube images and making them uncomfortable, making them difficult to view.

Conventionally, in order to solve this problem, a protective coating was applied to the surface of the cathode ray tube panel.Methods for preventing static electricity on cathode ray tubes can be roughly divided into the following two types.

The first method is to use moisture in the air. For example, as shown in JP-A-61-118932, this method involves stopping the decomposition midway through the decomposition process of alkoxides such as ethyl silicate, and converting -8 into a part of the 5t-0-8i siloxane structure.
>-OH silanol groups are left in a portion to improve moisture adsorption and provide a charging function.

The second method is to form a transparent conductive film that is itself conductive. For example, as shown in Utility Model Publication No. 49-24211,
After spray coating with a conductive solution, the film is baked at 450° C. to form a transparent conductive film.

Alternatively, it may be formed by a method such as vacuum evaporation or sputtering. Also, JP-A-62-15454L) and JP-A-62-15454L)
As shown in No. 2-116436, transparent conductive films and ultrafine conductors #j! Form into strips or mesh shapes.

[Problem to be solved by the invention]

The first method of using moisture in the air has no problems in areas with relatively high humidity, but does not provide antistatic properties at all when used in areas with low humidity. In addition, in order to retain some of the silanol group -di-OH in the film structure, the film formation temperature cannot be raised too high (if it is raised too high, all Sr - (J-di simixane structure will be formed), so it is no more than 80°C. At this temperature, the film strength is very weak, and it will peel off when wiped with a cloth or the like.

Among the methods of imparting conductivity to the second film or the wire itself, liquid coating methods such as spray coating do not produce a strong film unless baked at a temperature of 500 to 600°C after coating, and do not produce a strong film when heated at a temperature of 450°C or higher. If the surface resistance is not fired, the surface resistance will be less than 10 QΩ/unit (this will not go down). When applying methods such as vacuum evaporation and sputtering to cathode ray tubes, the object is large, so a very large vacuum device is required, and the price is high. However, this method of forming a transparent conductive film in the form of strips increases the number of layer steps and increases the production cost.

Forming ultra-fine conductive wires into strips has many problems in terms of cost and performance.

The purpose of the present invention is to enable coach ink even at a low temperature of 200°C or lower, and therefore to be able to directly coat a real ball, resulting in a very low 11t1'iw! It is an object of the present invention to provide a method for manufacturing a cathode ray tube that can fully satisfy the characteristics.

[Means for resolving stock issues]

The above purpose is to use 8nO, which itself has transparent conductive properties.
, In2O5,Sb, 0. and fine particles of a mixture of these, alkyl silicate) = 5t-(OR), (R
: Alkyl group) mixed with an alcohol solution was applied to the surface of the cathode ray tube panel, and then 20 minutes
This is achieved by forming an antistatic film through heat treatment at a temperature of 0° C. or lower.

[Effect]

Using fine particles that themselves have transparent conductive properties (
Therefore, the decomposition temperature of about 500° C., which is required in the conventional liquid coating method where the organic metal decomposition reaction is hot, is not required at all, and a temperature of 200° C. or less is sufficient.

In addition, since they are fine particles (less than a few thousand λ), they are almost invisible to the human eye, and light scattering is not bothersome.
It is a completely transparent film. Also, what connects the particles is 8.
t-(0l)4, which is 200°C for 30 minutes to form a light beam (if the glass is firmly attached to the layer, it will be mixed, and this will act as a binder and harden the transparent conductive fine particles). In order to harden, the strength is the same as above.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. An antistatic film 2 is formed on the panel surface of the cathode ray tube 1. The antistatic film 2 has a reinforcing band 3 connected to the ground.
The ball was in contact with the ground, and the entire surface was broken, keeping it in 11th place.

The antistatic film 2 is formed as follows.

For example, SnO, which itself has a transparent conductive function.

■n, 0. , 8b203 and their mixtures, or any of the fine particles of ethyl silicate 5t-(O
#I solution is prepared by thoroughly dispersing and mixing C2HJ4 in an alcohol solution. A suitable dispersant and a small amount of a catalyst to promote decomposition are added to this solution. In addition, when the size of Brown-#t1 is 20 inches, about 1 ton and 1 ml of the bath liquid is consumed.

Next, with the panel side facing up, drop the above solution onto the panel surface of the Braun 11 which is rotating at 10 rpm, and when it is completely distributed, increase the rotation speed to 500 rpm to spread the solution thinly and uniformly. Coat. This spin control is completed in a total of 1 minute.

Thereafter, it is dried by heating at 105°C for about 10 minutes, and then baked by heating at 160°C for 30 minutes. This results in
An antistatic film 2 is formed.

FIG. 2 shows the charge decay characteristics of a 20-inch color display tube. In the figure, 4 is the one on which the #electric protection film according to the present invention is formed, 5 is the one with the surface rM that is not treated at all, and 6 is the one whose surface is coated with only an alcohol solution of ethyl silicate. , 160° C. for 30 minutes to partially retain silanol groups and to have a C-teiden prevention film.

As is clear from the figure, the color display tube with the antistatic film of the present invention reaches a voltage of 0KV in about 10 seconds or less, while the other display tubes maintain a voltage of 20KV or more even after 5 minutes. It can be seen that the stem-reducing properties are very poor.

Next, we will discuss the results of investigating changes in surface resistance of cathode ray tubes with the antistatic film of the present invention.

Antistatic film No. 50- of Lion Office Equipment Co., Ltd.
The change in surface resistance before and after rubbing 250 times with a No. 50 eraser under a load of 1 kg was less than one digit. In addition, Johnson Co., Ltd.'s Glass Crew (product name)
The change in surface resistance value before and after rubbing 0 times was less than 0.5 digit. The change in surface resistance before and after being immersed in a tropic Tuda liquid of -=12 at room temperature for one day and night was also within one digit. Also, the surface resistance value when placed in a drying oven at 120°C for 96 hours. There was no change at all.

In this way, there is no problem with the antistatic function, and the antistatic function is fully exhibited under any environment.

Here, In, 0. has a feature of lower resistance than 5n021.

[Effect of the invention J According to the present invention, coating can be performed at 200°C or lower, so it is possible to directly coat a real ball, and it is easy to
It is possible to form inexpensive and highly durable sections. In addition, since the high potential charge on the surface of the cathode ray tube panel can be instantly removed, contamination caused by dust pots in the atmosphere is eliminated, and the display clarity of images, etc. is maintained at all times, and the display surface This also avoids electrical discharges that occur against human bodies that are close to the body.

[Brief explanation of the drawing]

FIG. 1 is a schematic external view showing an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the attenuation characteristics of Brown vi/')a electrons. 1. Bra-fun a, 2. Tei'ichi prevention film. Figure 1.2 Figure table Shizuma (minute)

Claims (1)

[Claims] 1. SnO_2, In itself has transparent conductive properties
_2O_3, Sb_2O_3, and fine particles of a mixture thereof are mixed into alkyl silicate=Si-(OR)_4 (R:
1. A method for manufacturing a cathode ray tube, which comprises coating the surface of a cathode ray tube panel using a solution mixed with an alcohol solution of (alkyl group) and then heat-treating at a temperature of 200° C. or less to form an antistatic film.