JPS63207031A - Manufacture of color cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent the exfoliation of carbon stripes of a color CRT by manufacturing the tube with the use of outside exposure procedure after the providing of a transparent protective film of a photo-setting resin on the glass panel on which carbon stripes are produced. CONSTITUTION:A transparent protective film 3 of a photo-setting resin which causes no depolymerization in reaction to hydrogen peroxide is provided on the whole surface of a glass panel 1 on which matrix type carbon stripes 2 are produced. A photoresist film 4 is then applied on the film 3 and developed after exposing red color and blue color portions, so photoresist film 4a corresponding to these color portions is left on the film 3. Next, green phosphor slurry 6 is applied on the whole surface of the panel and exposed from outside, and when inversion development with hydrogen peroxide is made green color stripes 6a are formed. Stripes of the other colors are also formed in the same way, the carbon stripes are prevented from exfoliation by the protective film, so that a color CRT of high precision can be manufactured.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing a color cathode ray tube with ultra-high definition, and in particular to a method for removing a black matrix (carbon stripe) in an external exposure method. It provides methods to prevent this.

[Summary of the invention]

In the present invention, when manufacturing a high-definition color cathode ray tube by the so-called external exposure method, a protective film made of a transparent photosensitive material is provided in advance on a glass panel on which a black matrix is formed. This is intended to prevent the black matrix from peeling off from the glass panel due to reversal development performed in subsequent steps.

[Conventional technology]

In order to reproduce highly detailed images on a color cathode ray tube, extremely fine phosphor stripes (or dots) of the three primary colors are clearly separated on the phosphor screen by a black matrix, which is a light absorption layer. Must have been. If this separation is not performed perfectly, the system will be strongly affected by mislanding of the electron beam during actual operation, taking into account various errors, and this will cause a significant deterioration in image quality. Therefore, research has been conducted in various fields on methods of forming a phosphor screen with clear edges of each phosphor and a high packing density.

The most common conventional method for manufacturing color cathode ray tubes is the so-called internal exposure method. This involves coating a glass panel with a predetermined pattern of carbon stripes on it, applying a phosphor slurry in which pigments are dispersed in a photocurable resin, exposing it to light through an optical mask, and developing it so that it does not harden. A striped color phosphor screen is manufactured by sequentially repeating the process of removing the parts for three colors, red, green, and blue.

In addition, as an improvement method for the above-mentioned inner surface exposure method, the applicant of the present application has previously proposed in Japanese Patent Application Laid-Open No. 119055/1982 a method to prevent color mixing between adjacent stripes by using two types of photosensitizers with different reversal abilities. , disclosed a so-called external exposure method. This consists of a glass panel with carbon stripes formed in advance, a resist layer using a first photosensitizer that can be reversed with hydrogen peroxide, and a second photosensitizer that is not reversible with hydrogen peroxide and a fluorescent dye. A phosphor screen is created by applying and curing a phosphor slurry in which phosphor particles are dispersed in a predetermined order.

[Problem that the invention seeks to solve]

By the way, in the above-mentioned inner surface exposure method, since the phosphor stripes are printed through an optical mask, there are problems such as half shadows, and the lack of adhesive strength between the phosphor stripes and the inner surface of the glass panel results in fine details. It was difficult to form phosphor stripes with distinct edges.

Although the external exposure method proposed by the applicant of the present invention overcomes the above-mentioned drawbacks of the conventional internal exposure method, there are still some problems that cannot be solved. In other words, in the external exposure method, reversal development is always performed once when forming a phosphor stripe of one color, so reversal development must be performed three times to complete a phosphor stripe of three colors. . However, when the resist layer is repeatedly inverted, that is, dissolved and removed in this way, the carbon stripes in contact with the resist layer are gradually eroded and peeled off, causing the manufactured phosphor screen to deteriorate. This means that the quality deteriorates.

Therefore, an object of the present invention is to provide a method that can prevent peeling of carbon stripes without significantly changing the above-mentioned process.

[Means for solving problems]

The present invention has been made in view of such circumstances,
After forming a light absorption layer with a predetermined pattern on the inner surface of the panel,
A step of applying a photosensitive resin to cover the entire inner surface of the panel and exposing the entire surface to form a protective film, and then forming a resist layer on areas other than the area where the first color phosphor slurry is applied; A step of applying a phosphor slurry made by mixing a first color phosphor into a photosensitizer that cannot be removed by the reversing agent of the resist layer, a step of exposing the entire panel to light from the outside surface and developing it, and a step of applying the reversing agent. removing the phosphor in the other portions together with the resist layer using The present invention provides a method for manufacturing a color cathode ray tube.

[Effect]

A transparent photo-curing resin that does not depolymerize with hydrogen peroxide is applied to a glass panel with carbon stripes formed on it! If the film is provided in advance, the carbon stripe is completely isolated from the phosphor stripe and resist m formed in the subsequent process by this protective film, and there is no risk of peeling even if the reversal process is repeated. Since the protective film is optically transparent, it does not interfere with light irradiation performed in subsequent steps.

〔Example〕

Examples to which the present invention is applied will be described below.

When creating a fluorescent surface for a color cathode ray tube, carbon stripes are first formed. That is, for example 2
A polyvinyl alcohol (PVA) photosensitive liquid is applied to the inner surface of a 0-inch color cathode ray tube glass panel and dried. On the other hand, UV exposure is performed using the aperture grill as an optical mask.

At this time, the ultraviolet light source is positioned correctly at the center of polarization of each of the red, green, and blue light sources, and the exposure is repeated three times. By developing this panel, a large number of A striped resist layer is formed.Next, a carbon film is applied to the entire surface of this panel.
When reversal development is performed after applying and drying the slurry, the carbon on the resist peels off together with the resist layer, and as shown in FIG.
A large number of carbon stripes (2) with a thickness of m are formed.

Next, a protective film is formed on this. The materials used here have good adhesion to the black matrix and glass panel, good wettability (can be applied thinly and evenly on the black matrix and glass panel, optical transparency, Polyvinylpyrrolidone-azide photosensitive resins, diazo photosensitive resins, etc. are used as materials that can achieve the objects of the present invention, which require properties such as having sufficient coating strength and not being dissolved in a reversal developer. photosensitive resins, and polyvinyl alcohol-stilbazolium photosensitive resins (hereinafter abbreviated as PVA-38+1 photosensitive resins), but among these, PVA-3BQ photosensitive resins are particularly suitable under the above conditions. It is suitable as satisfying.

The structural formula of PVA-5BQ photosensitive resin is expressed as follows, and this is a photosensitive resin in which a side chain of a stilbazolium group is bonded to a main chain of polyvinyl alcohol via an acetal structure. Since its side chain is a quaternary ammonium salt, the resin itself has sufficient hydrophilicity for practical use.

This PVA-5BQ photoresist resin is made into a 1.5% aqueous solution and applied to the entire surface of the glass panel (1) on which carbon stripes (2) are formed. PVA-5BQ at this time
The concentration of the photosensitive resin should be between 0.5 and 3%; if it is lower than the above range, the coating film tends to be thinner and uneven coating is likely to occur, and peeling of carbon stripes can be completely prevented. I can't. Moreover, if it is higher than the above range, the coating film tends to be thick, making it difficult for sufficient photocrosslinking to occur, and the coating film strength becomes insufficient, making it easy for the coating film itself to peel off during reversal.

Next, the PVA-5BQ photosensitive resin is polymerized by light irradiation. For this purpose, it is necessary to know the photochemical properties of this photosensitive resin. FIG. 1 shows the absorption mill M (1) and photopolymerization sensitivity curve (II) of PVA-3BQ photosensitive resin. From this figure, PVA-3BQ photosensitive resin is 340 n
It can be seen that it has an absorption maximum at m, and its sensitivity is good from the ultraviolet region to around 450 nm in the visible region. Therefore, for example, ultra-high pressure mercury lamps, UV fluorescent lamps,
Alternatively, a blue lamp or the like that is safe for the eyes can be used. n
The amount of light should be 50 mJ or more to ensure sufficient coating strength. Through this exposure, the PVA-5BQ photosensitive resin undergoes photopolymerization and hardens, and a protective film (3) with a thickness of 0.2 to 1 μm is formed on the panel (1) as shown in FIG. 2(B). Ru. Note that in this example, a UV fluorescent lamp was used.

Next, as shown in FIG. 2(C), the above-mentioned fill! (3
) Polyvinyl 7Jlz:l-/L/(PVA-ADC) photosensitive liquid containing a small amount of ammonium dichromate (4)
Apply and let dry.

Next, as shown in FIG. 2(D), exposure is performed using the aperture grille (5) as an optical mask using a normal exposure method. For example, when forming green phosphor stripes, red and blue It is sufficient to cover the positions corresponding to the stripes with an aperture grill (5) and perform exposure from the R (red) direction and the B (blue) direction in the figure. The exposed area is cured by photopolymerization and becomes Pv^-ADC.
A resist layer (4a) is formed, and the unexposed portions are removed by washing with water, resulting in the state shown in FIG. 2(E). Above P
The VA- to C resist layer (4a) can be reversed (dissolved and removed) with hydrogen peroxide solution.

Next, as shown in Figure 2 CF), a green phosphor slurry (6
) is applied to the entire inner surface of the panel, and the entire surface is exposed from the outer surface of the panel.

This PVA-5BQ photosensitive resin is not reversed by hydrogen peroxide solution, and when this panel is developed, it leaves a green phosphor stripe (6a) and a green phosphor cured area (6b) that are cured by photopolymerization and fluoresces green. The body slurry is removed, resulting in the state shown in FIG. 2(G).

Here, a green phosphor cured part (6b) remains also on the PVA-ADC resist 1it (4a), but this is PVII-ADC resist 1it (4a).
This is because since the ADC resist layer (4a) is transparent, the irradiation light reaches this portion and causes photopolymerization.

Next, when this state is immersed in hydrogen peroxide solution, which is a reversal agent, and reversal development is performed, the PVA-ADC resist layer (
4a) is dissolved and removed, and as a result, a green phosphor cured portion (6b) is formed on the resist layer (4a).
is also removed. As a result, as shown in Figure 2 (H),
Only a 15-20 μm thick green phosphor stripe (6a) remains.

If the steps from FIG. 2 (C) to (H) are repeated for other colors as well, the red phosphor stripe (7) and the blue phosphor strip are finally shown in FIG. 2 (1). Stripes (8) are formed and the phosphor screen is completed.

According to this example, no peeling of the carbon stripes was observed, and a good phosphor screen was obtained.

〔Effect of the invention〕

As is clear from the above explanation, in the present invention, the PVA-3BQ photosensitive resin is applied in advance before forming the phosphor stripes, so the peeling off of the carbon stripes, which was a problem in the conventional method, is effectively eliminated. It is possible to manufacture a color cathode ray tube with good image quality. In addition, since the protective film and the phosphor stripe formed on it are made of the same material, the adhesion of the phosphor stripe to the panel is improved, making it possible to create new products without significantly changing the conventional manufacturing process. Therefore, it becomes possible to provide a color cathode ray tube having a phosphor screen with high brightness.

[Brief explanation of the drawing]

Figure 1 is a spectrum diagram showing the absorption and sensitivity of PVA-3BQ photosensitive resin, which is the material of the protective film, and Figure 2 (A)
1) is a cross-sectional view showing an example of a method for manufacturing a color cathode ray tube to which the method of the present invention is applied in the order of steps; FIG. 2(A) is a step of forming carbon stripes, and FIG. Formation process of protective film, Figure 2 (C) shows PVA
- ADC photosensitive liquid coating process, Figure 2 (D) is the inner surface exposure process, Figure 2 (E) is the PVA- to C resist layer formation process, and Figure 2 (F) is the green phosphor slurry coating process. Coating and external exposure process, Figure 2 (G) is the development process, Figure 2 (H) is the process of forming green phosphor stripes by reversal development, the second
Figure (1) shows the state in which green, red, and blue phosphor stripes are formed. 1...Glass panel 2...Carbon stripe 3...Protective film 4a ---PVA-ADC resist layer 6...Green phosphor slurry

Claims (1)

[Claims] After forming a light-absorbing layer in a predetermined pattern on the inner surface of the panel, applying a photosensitive resin so as to cover the entire inner surface of the panel, and exposing the entire surface to light to form a protective film, a resist layer is applied as a first color. A step of forming the phosphor slurry on other parts than the part to be coated, and applying a phosphor slurry made by mixing the first color phosphor into a photosensitive agent that cannot be removed by the reversing agent of the resist layer. A first color phosphor stripe is formed by a step of exposing the entire surface to light from the outside of the panel and developing it, and a step of removing the phosphor in the other parts along with the resist layer using the reversing agent. and similarly forming at least a second color phosphor stripe.