KR19980084135A - Cathode ray tube with charge and antireflection film - Google Patents

Abstract

The present invention relates to a cathode ray tube surface having an antistatic and antireflection function on the surface of the cathode ray tube, and particularly suitable for enhancing an antistatic function and reducing a leakage electric field during operation of the cathode ray tube. SnO ₂ ), an agent having an antistatic film composed of silicon oxide (SiO ₂ ) having at least one fine particle and transparent conductivity among conductive metal oxides of indium oxide (In ₂ O ₃ ) and antimony oxide (Sb ₂ O ₃ ) A coating film of one layer is formed, and on the coating film of the first layer is composed of silicon oxide (SiO ₂ ) having at least one kind of fine particles and transparent conductivity and transparent protective property of the conductive metal oxide at the same time, antistatic and antireflection The coating film of the 2nd layer which has a function is formed and it is the technique with respect to the cathode ray tube characterized by the above-mentioned.

Description

Cathode ray tube with charge and antireflection film

The present invention relates to a coating film having an antistatic and antireflection function on a panel surface of a cathode ray tube, and more particularly, to a cathode ray tube surface suitable for enhancing an antistatic function and reducing a leakage electric field during operation of a cathode ray tube.

When a person's hand directly touches the front part (panel) of the cathode ray tube, it is strongly impacted by the high voltage static electricity charged on the panel surface. Furthermore, the charged panel surface absorbs air dust and accumulates the panel surface. It is difficult to see a clear image by making it dirty.

In addition, since the panel is glassy, it strongly reflects external light, making the image formed on the panel difficult to read.

As such, the demand for having an antistatic function and an antireflection function at the same time increases considerably.

1 is a schematic view showing a longitudinal cross-sectional view of a conventional cathode ray tube structure, which is composed of a panel 1 and a funnel 2.

On the outer surface of the panel (1), a coating film (single layer) is formed to simultaneously have an antistatic function and an anti-radiation function of external light to remove the electric charge generated on the front when the power is turned on or off. 1) A two-layer coating layer having an antistatic film 3 and an antireflection film 4 is formed on the outer surface.

Then, the conductive tape is grounded around the edge of the coating layer.

A method of forming such coating films (single layer and two layers) has been proposed in Korean Patent Publication No. 92-2531.

The method is uniformly added by adding a conductive metal oxide of tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), and antimony oxide (Sb ₂ O ₃ ) to an alcohol solution of alkoxysilane [Si (OR ₁ ) ₄ ]. A single layer made of a transparent conductive SiO ₂ film layer (also referred to as a transparent conductive film) that dissolves and disperses the coating liquid on the outer surface of the panel (1), and then calcinates at a low temperature to simultaneously provide an antistatic and antireflective function with a transparent and fine uneven surface. To form a coating film or to coat the same coating liquid on the outer surface of the panel (1) and then heat treatment at a relatively low temperature to form an antistatic film (3) and to the upper surface of the alkoxysilane [Si (OR ₁ ) ₄ ] The suspension dispersed by adding SiO ₂ to the alcohol solution was secondly applied with a spray and fired to form an antireflection film 4 having fine uneven portions on the surface.

However, in the coating layer, the transparent conductive film is effective in antireflection, but there is a limit in fundamentally improving conductivity.

In addition, conductivity is deteriorated due to excessive spray pressure during spraying and particle size problems of the supernatant.

The present invention has been made in order to solve the above-mentioned problems, using the same raw material to be coated on the upper and lower layers, but with a different composition of the content of the conductive raw material, the lower layer is coated with spin, the upper layer The purpose of the present invention is to obtain a cathode ray tube suitable for improving the conductivity problem, which is a conventional drawback, while having an antireflection function by spraying or rotating coating.

1 is a schematic view showing a longitudinal cross-sectional view of a conventional cathode ray tube;

Figure 2 is a longitudinal cross-sectional view of the coated cathode ray tube having a charge and antireflection function according to the invention

3 is a coating process diagram according to the present invention

Explanation of symbols for main parts of the drawings

DESCRIPTION OF SYMBOLS 1 Panel 6: Coating film of 1st layer

7: coating film of the second layer

The present invention for achieving the above object is a tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), antimony oxide (Sb ₂ O) on the outer surface of the panel (1) of the cathode ray tube as shown in FIG. ₃ ) a coating film 6 of a first layer, which is an antistatic film containing at least one kind of fine particles and composed of silicon oxide (SiO ₂ ) having transparent conductivity, is formed from the conductive metal oxide of ₃ ), and the first layer is coated. A second layer having an antistatic function and an antireflection function on the film 6 made of silicon oxide (SiO ₂ ) containing at least one kind of fine particles of the above conductive metal oxide and simultaneously having transparent conductivity and transparent protective property. It consists of the cathode ray tube which consists of the coating films 7 of.

The coating liquid for forming the coating film of the first layer (lower layer) and the second layer (upper layer) is a silane compound, which is a compound that becomes a silicasol after a hydrolysis reaction, that is, silane alkoxide, silicon halide, or the like. And mixed solvents of alcohols with carboxylic acid esters, water, and acids as hydrolysis reaction catalysts.

The coating liquid obtained by adding, dispersing, and dissolving the above-mentioned conductive oxide particles to such a silica sol liquid is used.

Solids (S ₂ ) composed of conductive particles in the solution to be coated on the upper layer is 1.0 to 4.0 wt%, solids (S ₁ ) composed of conductive particles in the solution to be coated on the lower layer is 1.0 to 2.0 wt% (Solid content is expressed as the weight percentage of the residual amount of calcined solution to the solution before firing after heating the solution at 1,000 ° C. for 60 minutes).

The phase, it is preferred that the solid content ratio (S ₂ / S ₁₎ of the lower layer solution was 0.5 to 4.0.

When the ratio of solids is 0.5 or less, it is difficult to obtain an effective uneven film due to the spray of the upper layer, and the antireflection effect is lowered. The resolution becomes worse.

The film thickness of the upper layer and the lower layer is preferably 500 to 1,500 Pa, 500 to 1,100 Pa, and the film thickness ratio (upper / lower layer) is preferably 0.5 to 3.0.

In the case where the film thickness ratio is 0.5 or less, it is difficult to form a uniform uneven film on the panel surface, and the antireflection effect is lowered, and the effect of imparting conductivity to the upper layer is also lowered.

In addition, if the thickness ratio exceeds 3.0, the thickness becomes thick during spraying, and the effect of imparting conductivity is improved, but screen characteristics are deteriorated.

The following is described according to the embodiment.

Figure 3 shows the coating process of the present invention, the surface of the panel is subjected to Cerox polishing and cleaned.

After preheating the surface at 30 to 60 ° C., spin the undercoat as shown in Table 1 below (spinning condition: rpm: 100, time: 50 to 70 seconds), and then preheat the surface to 80 to 100 ° C. Then, the upper coating solution is applied by a spray method.

Finally, it was calcined at 150 to 200 ° C. for 1.5 hours.

TABLE 1

Upper coating liquid Undercoat Coating Alcohols: 81 (methanol, ekanol, n-butanol, etc.) Alcohol: 97 Water: 15 Water: 1 Other Solvents: 1 Other Solvents: 0.5 Sb-SnO ₂ : 3SiO ₂ HNO ₃ Sb-SnO ₂ : 1.5SiO ₂

The results according to the above example are shown in Table 2.

That is, the present invention has a stable antistatic effect and the leakage electric field coming out of the surface during the cathode ray tube driving regardless of the change over time as shown in Table 2 by having the function of the upper layer to the anti-reflection and anti-static function in the conventional anti-reflection function By effectively reducing the power of the human body from the current electromagnetic wave has the advantage that can be solved.

TABLE 2

Item (unit) Conventional The present invention 1.Surface Resistance (Ω /?) 10E7-10E8 10E6 2. dischargl time (sec) 10 1 (sec) or less 3. Glossiness (%) 65 ± 5 Left 4. Leakage field (v / m) 1.5 0.7 to 0.9 Note 1) discharge time; The time when the surface potential falls below 500 V when the CRT power switch is turned ON or OFF. 2) Leakage field; This is a circuit compensation method on the monitor set. The distance between the front face and the measuring pores is 30 cm.

As described above, the present invention forms a first layer having an antistatic function and a second layer structure having an antistatic and antireflection function on the panel outer surface of the cathode ray tube, thereby enhancing a stable antistatic function regardless of changes over time. When the cathode ray tube is operated, an effect of reducing the leakage field can be obtained.

Claims (4)

Silicon oxide (SiO ₂₎ having at least one fine particle and transparent conductivity among conductive metal oxides of tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), and antimony oxide (Sb ₂ O ₃ ) on the panel surface of the cathode ray tube A coating film of the first layer having an antistatic film composed of Application of the second layer having antistatic and antireflective functions composed of silicon oxide (SiO ₂ ) having at least one kind of fine particles and transparent conductivity and transparent protective property among the conductive metal oxides on the coating film of the first layer. Cathode ray tube, characterized in that the film is formed. The method of claim 1, A cathode ray tube, characterized in that the coating film of the first layer is formed of spin coating and the coating film of the second layer is formed of spraying or rotation coating. The method of claim 1, Solid content (S ₂ ) of the conductive metal oxide in the coating liquid of the second layer was 1.0 to 4.0 wt%, solid content (S ₁ ) of the conductive metal oxide in the coating liquid of the first layer was 1.0 to 2.0 wt%, and these solid contents Cathode ray tube, characterized in that the ratio (S ₂ / S ₁ ) is 0.5 to 4.0. The method of claim 1, The coating film thickness t ₂ of a 2nd layer is 500-1,500 kPa, A cathode ray tube, characterized in that the coating film thickness t ₁ of the first layer is 500 to 1,100 kPa, and their coating film thickness ratio (t ₂ / t ₁ ) is 0.5 to 3.0.