JPH05325838A - Cathode-ray tube and manufacture thereof - Google Patents

Abstract

PURPOSE:To enhance the anti-reflection and anti-static functions of a cathode- ray tube by spraying the display screen of the cathode-ray tube with a solution composed chiefly of an Sn organic metal compound, and exposing the display screen to light, thus forming a monolayer thin film having specific sheet resistance and microscopic irregularities. CONSTITUTION:The display screen of a cathode-ray tube 1 is covered on its outer surface by spray coating of a solution comprising an organic solvent, such as ethanol having an Sn organic metal compound dissolved therein with an Sb organic metal compound added thereto by a small quantity. Light of wavelengths 300nm or less is applied to the coated surface in the presence of ions and heating is performed at temperatures 200 deg.C or less. As a result, a monolayer thin film 2 composed chiefly of SnO2 and having transparency and micro irregularities is formed with a sheet resistance of not more than 10<8>OMEGA/sq.inch. The film 2 has both anti-reflection and anti-static functions. The glare-proof, antistatic cathode-ray tube is thus provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube in which at least a display surface of the cathode ray tube is provided with an antistatic function and an antireflection function, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, cathode ray tubes having an antireflection function or an antistatic function on a display surface of the cathode ray tube have been widely manufactured. The antireflection function is a function of suppressing reflection of external light on the display surface of the cathode ray tube and making the displayed image easy to see. The antistatic function prevents the display surface of the cathode ray tube from being charged,
This is a function to prevent the adsorption of dust due to electric shock or electrification on the human body. It is known that an antireflection film or an antistatic film is formed on the outer surface (face surface) of the cathode ray tube display surface in order to impart the above function. It has been proposed that a single film of an antireflection film or an antistatic film or a laminate of an antireflection film and an antistatic film is provided with both functions.

For example, it is known that a alkoxide solution of silicon is sprayed and heat-treated to form fine irregularities on the display surface of a cathode ray tube to form an antireflection film (Japanese Patent Publication No. Sho 6).
No. 2-143348). It is also known that an antistatic film is formed by spraying a solution of a silicon alkoxide containing fine particles of tin oxide or indium oxide. Furthermore, as a laminate of an antireflection film and an antistatic film, Japanese Patent Publication No. 63-76247 and Japanese Patent Publication No.
There are Japanese Patent Publication No. 72549 and Japanese Patent Publication No. 1-286240. In all of these, an antistatic film containing fine particles of tin oxide or indium oxide is formed on the antistatic film, and an antireflection film of SiO ₂ having fine irregularities is formed thereon. As a method for forming these films, a CVD method, a sputtering method and the like are known in addition to the spraying method.

[0004]

However, until now, a cathode ray tube having only an antireflection film has no antistatic function and is functionally insufficient. Further, in a cathode ray tube having only an antistatic film in which conductive ultrafine particles are dispersed in a SiO ₂ film, the mechanical strength is weak, the adhesive force to the display surface of the cathode ray tube is also weak, and the sheet resistance is 10 ⁸ to 10 ⁹ Ω / □ was high, and the antistatic function was insufficient. On the other hand, ITO (In
_{The one using 2} O ₃ + Sb ₂ O ₃ ) is not suitable because the strength of the film itself is weak.

In the case where the antireflection film is laminated on the antistatic film, the antireflection film serves as a protective film to improve the mechanical strength of the film, but since the film is laminated in two layers, the manufacturing process is reduced accordingly. There is a problem in terms of productivity because it increases.

There is also a film formed by the CVD method or the sputtering method, but the productivity is poor and the film forming temperature is 5
There is also a drawback that it cannot be applied to a cathode-ray tube completed sphere, such as that the temperature is 00 ° C. or higher and that the film must be formed in a high vacuum state.

An object of the present invention is to provide a CRT having a monolayer film having both mechanical functions of antireflection and antistatic function and excellent mechanical strength.

Another object of the present invention is to provide a method for producing a cathode ray tube having both the antireflection function and the antistatic function, which has good productivity.

[0009]

The gist of the present invention for solving the above problems is as follows.

(1) SnO ₂ having fine irregularities with a sheet resistance of 10 ⁸ Ω / □ or less on the outer surface of the display surface of a cathode ray tube.
CRT with a single-layer thin film mainly composed of

(2) The outer surface of the display surface of the cathode ray tube is SnO.
A cathode ray tube having an antistatic film consisting of a single-layer thin film consisting mainly of ₂ , the surface of the thin film having fine irregularities that diffusely reflect external light.

(3) A thin film containing SnO ₂ as a main component, which is transparent and has fine irregularities, which is formed by spraying a solution containing a Sn-based organometallic compound as a main component on the outer surface of the display surface of a cathode ray tube and heating it while irradiating light. To make a cathode ray tube.

By the above, a CRT having an antireflection function and an antistatic function can be obtained.

As the Sn-based organometallic compound, there can be used tin acetate such as ethylhexanoate and naphthenate, alkoxide complex such as tetrabutoxytin, and acetylacetonato complex such as acetylacetone tin. Further, those in which an organic group such as dibutyltin acetate is directly bonded to tin, and those in which an alkoxy group or an acetylacetonato group are mixed and coordinated can also be used.

The above Sn-based organometallic compound is ethanol,
It is dissolved in an organic solvent such as butanol or acetylacetone, and a small amount of Sb-based organometallic compound is added thereto. This is spray coated on the display surface of the cathode ray tube. Then, the coating surface is irradiated with light having a wavelength of 300 nm or less. At this time, ozone coexists. In the light irradiation under the coexistence of ozone, heating at 200 ° C. or lower is performed. Sn
Since the organometallic compound has strong absorption at 300 nm or less, it is easily decomposed by irradiation with the light (ultraviolet light).
Further, ozone, which has a strong oxidizing power, efficiently oxidizes residual organic substances in the film to form a Sn-based oxide thin film. In this way, an antistatic film having a resistance of 10 ⁸ Ω / □ or less can be obtained.

Heating above 200 ° C. significantly lowers the performance and production yield of the cathode ray tube as a finished sphere.

[0017]

In the above, the reason why the wavelength of the irradiation light must be 300 nm or less is that the reaction of the spray coating film does not proceed sufficiently when it exceeds 300 nm. As a result, organic substances remain in the formed film, and the sheet resistance becomes larger than 10 ⁸ Ω / □, and the antistatic function is not sufficiently fulfilled.

Since fine irregularities are formed on the film formed by spray coating on the display surface of the cathode ray tube, external light is scattered to provide an antireflection function. Tin oxide is chemically very stable, exhibits high corrosion resistance to water, and has a large mechanical strength. Furthermore, from the viewpoint of controlling the valence, by adding Sb, F, or the like having different valences, holes or electrons in the formed film become conductive, thereby lowering the sheet resistance and charging. Preventive function is obtained.

[0019]

【Example】

Example 1 A 0.1 mol / l ethanol solution of stannous 2-ethylhexanoate, which is an organometallic compound of Sn, was prepared. To 50 ml of this solution was added 0.5 ml of a 0.1 mol / l ethanol solution of antimony butoxide. Furthermore, a 0.1 mol / l ethanol solution of water 2.0
After adding ml, 0.1 ml of a 0.1 mol / l ethanol solution of hydrochloric acid was added and reacted at 60 ° C. for 1 hour. As shown in the schematic diagram of FIG.
The display surface of was coated with a spray gun 3.

The Braun tube having the coating film 2 is attached to a fixed base 5 on a conveyor 4 of a manufacturing apparatus shown in the schematic view of FIG. The wavelength of 254 nm by the ultraviolet lamp 7,
UV light of 184 nm was simultaneously irradiated. Ozone is generated by simultaneously irradiating two ultraviolet rays having different wavelengths. At that time, the coating film 2 formed on the display surface of the cathode ray tube is heated to 160 ° C. The light irradiation-heating time of about 30 minutes is sufficient. As a result, a film having fine irregularities on the film surface and a sheet resistance of 8 × 10 ⁷ Ω / □ or less could be formed.

The film is a single layer and has both antireflection and antistatic functions. As a result of a boiling water immersion test of this film, no change in film quality or film peeling was observed even after 60 minutes.

Example 2 As an organometallic compound of Sn, 50 ml of a 0.1 mol / l ethanol solution of stannous 2-ethylhexanoate was prepared. N to 50 ml of the solution
0.5 ml of a 0.1 mol / l aqueous solution of H ₄ F was added, and 0.1 ml of a 0.1 mol / l ethanol solution of hydrochloric acid was further added, and the mixture was reacted at 60 ° C. for 1 hour. This reaction solution was spray-coated on the display surface of the cathode ray tube in the same manner as in Example 1, and the ultraviolet rays of 254 nm and 184 nm were simultaneously irradiated. As a result, it was possible to form a film having fine irregularities on the film surface and having a sheet resistance of 10 ⁷ Ω / □ or less.

The film is a single layer and has both antireflection and antistatic functions. When the film was subjected to a boiling water immersion test, no change in film quality or film peeling was observed even after 60 minutes.

[Comparative Example] A film spray-coated in the same manner as in Example 1 was exposed to the above-mentioned ultraviolet light.
Heated to 0 ° C. The sheet resistance of the film was 10 ¹¹ Ω / □, and the function as an antistatic film was not obtained. In the boiling water immersion test, the film peeled off in about 15 minutes.

In addition, a cathode ray tube having a film formed by dispersing ultrafine particles of SnO ₂ and Sb ₂ O _{3 in} a SiO ₂ sol solution which has been conventionally used as an antistatic film is used.
Heat treatment was performed at 0 ° C. The sheet resistance of the film is 3 × 10 ⁹ Ω /
□, and the function as an antistatic film was insufficient.
In the boiling water immersion test, the film peeled off in about 15 minutes.

[0026]

According to the present invention, a display screen of a cathode ray tube is spray-coated with a solution containing Sn-based organometallic compound as a main component, and is irradiated with light having a wavelength of 300 nm or less to make it transparent mainly containing SnO ₂ . The cathode ray tube on which a thin film having fine irregularities is formed exhibits excellent antireflection function and antistatic function. This makes it possible to obtain a Braun tube having antiglare and antistatic effects.

The heating temperature required for film formation is 200 ° C.
Since the following is sufficient, the heating and cooling time can be set to the conventional value (heating temperature 50
The temperature can be set to about 1/2 or less than 0 ° C.), which leads to improvement in productivity.

Furthermore, for the cathode ray tube which is a completed sphere, the low heating temperature for film formation has little influence on the characteristics of the electron gun of the cathode ray tube, and the production yield of the cathode ray tube can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention in which a film is formed on a display surface of a cathode ray tube.

FIG. 2 is a schematic view showing an embodiment of a light irradiation device of the present invention for forming a film on the display surface of a cathode ray tube.

[Explanation of symbols]

1 ... CRT, 2 ... Coating film, 3 ... Spray gun, 4 ... Conveyor, 5 ... Fixing stand, 6 ... Hood, 7 ... UV lamp, 8 ... Film forming solution.

Claims (6)

[Claims] 1. A cathode ray tube characterized in that a single layer thin film mainly composed of SnO ₂ having a sheet resistance of 10 ⁸ Ω / □ or less and fine irregularities is provided on the outer surface of the display surface of the cathode ray tube. 2. An outer surface of a cathode ray tube display surface has an antistatic film composed of a single-layer thin film containing SnO ₂ as a main component, and the surface of the thin film has fine irregularities for irregularly reflecting external light. CRT. 3. A thin film containing SnO ₂ as a main component, which is transparent and has fine irregularities, which is formed by spraying a solution containing a Sn-based organometallic compound as a main component onto the outer surface of the display surface of a cathode ray tube and heating it while irradiating light. A method of manufacturing a cathode ray tube characterized by forming. 4. The method for producing a cathode ray tube according to claim 3, wherein the solution containing the Sn-based organometallic compound as a main component contains an Sb or F-based compound. 5. The irradiation light having a wavelength of 300 nm or less, and the light is irradiated in the coexistence of ozone.
The manufacturing method of the cathode ray tube described in. 6. A cathode ray tube display surface is 200 when the light is irradiated.
The method for producing a cathode ray tube according to claim 3, 4 or 5, wherein the temperature is not higher than ° C.