JPS6022466B2 - Method for manufacturing a fluorescent surface of a color picture tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in a method for manufacturing a light surface of a black matrix type color picture tube.

In general, black matrix type color picture tubes,
On the light surface, anti-reflection graphite is coated between the three colored poppies and the light body pixels.

The formation of this light surface is usually done by first forming a graphite black matrix film with many holes on the inner surface of the panel, and then dot-shaped holes or stripe-shaped grooves (hereinafter referred to as both) formed in the black matrix. The process involves applying green, blue, and red phosphors to the predetermined shadows of the black matrix hole (together referred to as the black matrix hole) to form poppy and photopixel pixels. A specific example of the method for manufacturing this poppy light surface will be described. A photosensitive binder, such as polyvinyl alcohol mixed with ammonium dichromate, is applied to the inner surface of a panel, which is a glass substrate, to form a photoresist film, and then this photoresist film is placed a certain distance from the inner surface of the panel. exposed to light through a shadow mask. This exposure is carried out three times by slightly changing the position of the light source in order to correspond to the application positions of the normal line, the three colors of blue and red poppies, and the photopixel. After the exposed parts of the photoresist film are cured by this exposure, when the face is treated with hot water, the parts of the photoresist film other than the exposed parts are peeled off, forming dots or stripes of the photoresist film on the inner surface of the panel. . Next, on the inside of this panel,
The main component is fine graphite powder, which is mixed with a coating liquid to form a graphite film, which is then dried to form a graphite film.The graphite film is then immersed in hydrogen peroxide solution or sprayed. The remaining photoresist dots or stripes underlying the film are swollen and a hot water spray is used to remove the swollen photoresist along with the overlying graphite film to form a large number of dots or stripes as shown in FIG. A black matrix film 2 made of a graphite film having holes 1 or striped grooves (not shown), that is, black matrix holes is formed on the inner surface of the panel 3. In addition, the second
Figure 1 is a plan view of Figure 1, and Figure 1 is A-A of Figure 2.
'Shows a cross section. Next, a phosphor slurry containing a photosensitive binder is applied to the surface on which the black matrix is formed, and the phosphor slurry is exposed to light through a shadow mask and developed, so that the phosphor and phosphor slurry are applied to the predetermined positions of the black matrix holes. Form body picture elements. Figures 3 and 4 show this state.
4 is a phosphor picture element. In addition, Fig. 3 shows C- in Fig. 4.
〇Shows a cross section. This operation is performed separately for each poppy and light body of green (G), blue (B), and red (R).
In this way, the black matrix hole is filled with poppy and photopixel elements of three colors. And this poppy,
After the phosphor has been applied, a filming film is applied to make the surface of the phosphor picture element somewhat smooth, and then an aluminum film that becomes a light-reflecting film is formed on top of it by means such as vacuum evaporation. After going through processes such as heat treatment, the light surface of the black matrix color picture tube is completed.

However, in the above process, it is technically difficult to obtain a high-quality fluorescent surface.

That is, as shown in FIG.
A pinhole 5 may occur in the graphite film, causing light to leak and worsening the appearance of the fluorescent surface, or the graphite film may become splintered or adhere to the photopixel as shown in 6 in Figures 3 and 4. There are drawbacks such as poor placement and easy peeling of the photopixel. Pinholes 5 are likely to be formed in the graphite film of the black matrix 2 when the graphite particles applied here have a coarse particle size.

When coarse-grained graphite is applied to the inner surface of a panel, gaps are formed between the particles, and these gaps themselves become pinholes, and when hydrogen peroxide treatment is performed in a later process, excess gas is removed from the gaps. Hydrogen oxide water may penetrate and peel off the graphite film in curved areas, causing pinholes.Also, if the particles are rough, a thick layer of graphite may be applied to eliminate pinholes, but in general, graphite may be applied thickly to the inner surface of the panel. The thicker the coating, the more likely it will peel off. Therefore, in order to coat the inner surface of the panel with a highly adhesive graphite film without creating pinholes, it is best to use fine-grained graphite. Graphite with a fine particle size distribution is used as shown in Figure 5. As mentioned above, when graphite with a fine particle size distribution is applied, the adhesion between the graphite film and the inner surface of the panel is good, and there are no pinholes. However, on the other hand, since the surface of the applied graphite film becomes a delicate and smooth surface, the adhesion of the phosphor paint painted on it becomes poor. The disadvantage is that the material tends to peel off.

As shown in FIGS. 3 and 4, the diameter of the dots (or stripes) of the poppy and photopixel 4 is larger than the diameter of the black matrix hole, so the edges of the poppy and photopixel 4 are It is applied over the graphite film of the black matrix 2. Therefore, adhesion between the graphite film and the poppy and photopixel is very important in preventing the poppy and photopixel from peeling off. Therefore, in order to strengthen the graphite film and improve its adhesion to the photopixel, a certain amount of coarse particles should be mixed into the graphite.
It is preferable to make the surface of the graphite film applied to the inner surface of the panel uneven.

In the past, there have been attempts to mix coarsely grained graphite into graphite having a fine grain size distribution as shown in FIG. The inventors have carried out various studies through tests and other methods with the aim of obtaining a black matrix graphite film that adheres well to the inner surface of the panel, has no pinholes, and also has good adhesion to poppies and photopixels. As a result, we concluded that it is best to make a black matrix using graphite having the particle size distribution shown below.

That is, as shown in FIG. 6, which shows an example of the particle size distribution diagram of graphite used in the present invention, the particle size is divided into 0.2 increments, and the weight of graphite particles included in each particle size category and the particle size are calculated. When expressing the graphite particle size distribution diagram in relation to the classification,
The particle size distribution diagram has the largest peak, that is, the first maximum value, at a particle size of 0.4 or less, and the particle size i. The amount of graphite that has a shape with a second peak, that is, a second maximum value in the range of 0 to 1.4, and has a particle size in the range of 1.0 to 1.4, is 8 to 8 of the total amount of graphite. A black matrix is formed using graphite having a particle size distribution such that it accounts for 1% by weight of the matrix, and is then inserted into the black matrix holes to form photopixels, so that the graphite film of the black matrix forms on the inner surface of the panel. Creates a light surface for black matrix type color picture tubes that has good adhesion, without pinholes, and without peeling of the graphite film or the surface of the light body picture element. It became so.

In the particle size distribution diagram of the graphite used in the above-mentioned implementation of the present invention, the reason why the maximum value is below the particle size of 0.4 is because the adhesion of the graphite to the inner surface of the panel is improved by containing a large amount of fine particles. In addition, this fine particle graphite forms the second mountain with a particle size of 1.0
It fills in the gaps between relatively rough particles of ~1.4 µm and eliminates pinholes.

The presence of the second peak at a grain size of 1.0 to 1.4 μm strengthens the adhesion to the surface thorns of the graphite film and the photopixel, and Coupled with the presence of a mountain of fine particles, this constitutes an important element in achieving the objectives of the present invention. And also, this particle size is 1.0 to 1.
The amount of graphite in step 4 is preferably within the range of 8 to 16% of the total graphite.If this amount exceeds 16%, pinholes may form in the graphite film, or the graphite film may become stuck to the inner surface of the panel. If this amount is less than 8%, the adhesion between the graphite film, the embossment, and the photo element becomes easy to peel off. Generally, the particle size distribution of graphite powder has a maximum value at a certain value of the particle size, and exhibits a shape that gradually decreases at particle sizes before and after that value.

Therefore, in order to obtain graphite having a particle size distribution as shown in FIG. As shown in the figure, graphite has a particle size distribution in which the maximum value is within the range of 1.0 to 1.4 degrees, and when graphite of both distributions is blended, the graphite is in the range of 1.0 to 1.4 degrees. is 8~ of the whole graphite
It can be obtained by blending in an amount such that IQ weight % is achieved. As explained above,
By carrying out the present invention, it is possible to produce a light surface without peeling or pinholes of the graphite film of the black matrix, and without peeling of the bonding surface between the graphite film and the light body pixel. As a result, a black matrix type color picture tube with a high-quality poppy light surface can be obtained.

[Brief explanation of the drawing]

Figure 1 is an enlarged vertical cross-sectional view of the main part when a graphite film of the black matrix is formed on the inner surface of the panel, Figure 2 is a top view of Figure 1, and Figure 3 is a picture of the black matrix holes and light bodies. Fig. 4 is a top view of Fig. 3, Fig. 5 is a particle size distribution diagram of graphite conventionally used to form a black matrix, Fig. 6 is a graphite particle size distribution diagram An example of a particle size distribution diagram of graphite used in carrying out the present invention,
FIG. 7 shows an example of a particle size distribution diagram of graphite used for producing graphite having the particle size distribution shown in FIG. 1...Black matrix hole, 2...Flat matrix film, 3...Panel, 4...
Munashi/light body picture element, 5... pinhole in graphite film, 6...
...The area where the graphite film has peeled off and the photopixel has peeled off. Younger brother T figure Qin Z figure 3 figure 4 figure S figure Yume et al figure 7

Claims (1)

[Claims] 1 When the particle size of graphite is divided into 0.2μ increments and the particle size distribution diagram of graphite is expressed by the relationship between the weight of graphite particles included in each particle size category and the above particle size category, the particle size distribution diagram is the largest mountain in the particle size of 0.4μ or less, that is, the first
It has a shape having a second peak, that is, a second maximum value in the particle size range of 1.0 to 1.4μ, and has a particle size of 1.0 to 1.4μ. A color picture tube characterized in that a black matrix film is formed on the inner surface of the panel by using graphite having a particle size distribution such that the amount of graphite in this range accounts for 8 to 16% by weight of the total amount of graphite. Fluorescent surface manufacturing method.