JPS6039737A - Method of forming black matrix type phosphor screen - Google Patents

Abstract

PURPOSE:To obtain a stable black matrix type phosphor coat by coating the surface of a panel of which a PVA coated pattern is formed with light absorption material and removing a coat of a reaction section and the light absorption material on the coat and then cleaning the panel. CONSTITUTION:A coat is formed by coating the surface of a panel with a PVA solution containing dichromate as sensitizer. A cross-linking reaction is generated by locally exposing this coat and a coat of a non-reaction section is removed. The surface of the panel containing the coat is coated with light absorption material and a coat of a reaction section and the light absorption material applied on the coat are removed using an oxidizing agent solution such as H2O2. This panel is cleaned in a wet state using an NaOH aqueous solution. Subsequently the surface of this panel is coated with a slurry in which phosphor particles are diffused in a PVA sensitizing solution. Exposure is applied through a mask and phosphor picture elements are stuck to the gap of the light absorption material. Even when the oxidizing agent concentration is high, a black matrix type phosphor secreen can be formed without the slipping off of the phosphor picture elements by this method.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a black matrix type phosphor film in which a black matrix is provided on the inner surface of a panel of a color cathode ray tube, and then the surface is treated to form phosphor picture elements. This relates to a forming method.

[Prior Art] Normally, the fluorescent film of a color cathode ray tube consists of phosphor pixels with three types of emitting colors on the inner wall of the panel, and the areas between these phosphor pixels that do not contribute to light emission are filled with a light-absorbing material. It is composed of a black matrix and a black matrix.

In manufacturing the phosphor film for color cathode ray tubes, extremely high precision is required for the position and shape of the phosphor picture elements or black matrix, so optical photographic printing methods have traditionally been used. That is, to form the above-mentioned black matrix, a method such as that described above is adopted. First, after coating the inner surface of the panel with photosensitive polyvinyl alcohol (hereinafter referred to as PVA) to form a film, a shadow mask is attached to the pin with Ml threaded on the skirt part of the panel. A predetermined portion of the PVA film is exposed to ultraviolet light through the aperture of the shadow mask. Thereafter, the PVA film is developed by spraying hot water to remove the pVA II in the unexposed area, and a drastic turning force of the PVA film remains. Next, a light-absorbing substance such as graphite is applied to the inner surface of this panel, and then an oxidizing agent solution is applied to decompose the photo-crosslinked PVA film. If you remove this part of graphite, you will get 100g of black mud.

Furthermore, the phosphor picture element is coated with a phosphor slurry 1) in which the phosphor picture element is dispersed in a photosensitive PVA liquid on the inner surface of the panel provided with the above-mentioned black mud 1 NOX, and using a shadow mask, the above-mentioned By the same method as above, only the parts corresponding to the openings of the black matrix are exposed to light, and the photoreceptor particles are bound and left (flu is formed by a method that is removed by development. 1.X using two types of phosphor slurries
By repeating this process 111M times, a fluorescent film is completed.

By the way, in the method for producing a black matrix as described above, the oxidizing agent solution for decomposing the polymerized and cured PVA film has conventionally been an aqueous solution containing 4±1% hydrogen peroxide as a main ingredient, or an aqueous solution containing 0.05±0% hydrogen peroxide as the main ingredient. An aqueous solution containing .01% periodic acid or its salt as a main ingredient is used. However, even if the concentration of the base agent slightly exceeds the specified upper limit, the adhesion of the phosphor will be impaired in the subsequent step of attaching the phosphor picture elements, making it easy for local drop-offs to occur. When the concentration is close to the lower limit, insufficient decomposition of PVA occurs, and this concentration range is relatively narrow, which is a problem. In particular, in production equipment for mass production, metering pumps are used to automatically mix base ingredients with a specified high concentration and deionized water to achieve a predetermined concentration, but in reality, the concentration fluctuates due to errors in pump delivery. This may cause the above trouble.

[Summary of the Invention] This invention provides a light-absorbing material on the PVA coating and on the panel from which the coating has been removed! The coating on the reaction area and the light-absorbing substance coated on it are removed with an oxidizing agent solution, and then, while the nokuneru is still wet, it is washed with an aqueous sodium hydroxide solution. By doing this, the concentration of the oxidizing agent solution can be increased 1. ) The purpose of the present invention is to provide a method for producing a stable black matrix type phosphor film by preventing the falling off of phosphor picture elements that occurs in the case of oxidation, expanding the permissible concentration range of the acid solution.

[Embodiments of the invention] Examples will be described below.

(Example 1) Composition 1 Deionized water @11+1・Ro◆◆・150C Go 10%P
VA aqueous solution-・φ-・-30g Epan-450 (5%
Alcohol liquid) @ II +1 0.25 crri1
18%N-3DCe a * * * 4.2 cm'
After coating the photosensitive resist of the composition 1 to a thickness of about 0.9 microns on the inner surface of the panel of a 14-inch color cathode ray tube to form a film, placing a shadow mask at a predetermined position on the inner surface of the panel, Ultraviolet rays emitted from an ultra-high-pressure mercury lamp placed at a position corresponding to the deflection point of the electron beam are passed through a dimming filter and a correction lens to generate a power of 0.85 mW/c x 4.
Perform a 5-second exposure to complete the printing process. Exposure is performed sequentially using green, blue, and red light sources. After removing the shadow mask from the panel, hot water at about 50°C is uniformly sprayed onto the inner surface of the panel to dissolve and remove the resist in the unexposed areas, forming resist stripes. pattern is obtained. Next, apply 5% Akudak solution (Japan Atisonic Acid) with a pH of 10.5 to the inner surface of this panel.
After spraying, the temperature of the panel is raised to 58°C, and hydrogen peroxide solution of arbitrary concentration is injected.

After reacting for about 70 seconds, water was sprayed at a pressure of about 5 Kg/crrf for development, and a black matrix was obtained on the inner surface of the panel. Then, aqueous sodium hydroxide solution was poured over the surface, followed by washing with deionized water.

A slurry in which green phosphor powder is dispersed is applied to photosensitive PVA and dried. The phosphor film was exposed to light from a green light source potential using a method similar to the method for manufacturing the black matrix, and then developed, and green phosphor stripes were formed on the apertures of the black matrix.

By the way, in the above method, by changing the combination of the concentration of hydrogen peroxide solution and the concentration of sodium hydroxide solution, PVA
The results of investigating the relationship between the decomposition ability of
Summarize in a table.

Table 1 In the table, the Δ symbol for PVA decomposition ability indicates that the black matrix is slightly broken, while the X symbol for the phosphor adhesion indicates that more than lθ pieces have fallen off, and the 0 mark indicates that only a few pieces have fallen off. It represents. In the case of a conventional example that does not use an aqueous sodium hydroxide solution, the concentration of hydrogen peroxide solution is 6.5'wt.
%, the phosphor adhesive strength decreases. However, when a sodium hydroxide aqueous solution is used, even if the concentration of hydrogen peroxide solution is 6.5%, 0.05 w after graphite development.
Finish cleaning with a t% sodium hydroxide aqueous solution improves the adhesion and does not affect the ability to decompose PVA. Therefore, since the upper limit range of the concentration of the aqueous peroxide solution, which is the oxidizing agent solution, can be expanded to 8.5 wt%, it can be easily adjusted using an automatic device.

(Example 2) Table 2 lists the results of testing in substantially the same manner as in Example 1 above, except that the oxidizing agent solution was replaced with an aqueous solution containing sodium periodate as the main ingredient during the black matrix manufacturing process.

Table 2 As is clear from the results, in the conventional example that does not use a sodium hydroxide solution, the usable concentration range of the Na104 solution was limited to 0.03 to o.o.e.wt%; By finishing cleaning with an aqueous sodium hydroxide solution, the applicable concentration range is 0.03~
o, twt%.

In addition, in Example 1.2 above, a method was described in which PVA is decomposed with an oxidizing agent solution and then washed with a sodium hydroxide aqueous solution after the development of graphite is completed. It may also be used as an aqueous solution.

Further, it is effective to perform the final cleaning with an aqueous sodium hydroxide solution while the inner surface of the panel after graphite development is still undried.

[Effects of the Invention] As explained above, according to the present invention, a light-absorbing substance is applied on the PVA coating and on the panel from which the coating has been removed, and the coating in the reaction area and the light applied thereon are absorbed. Absorbing substances are removed with an oxidizing agent solution, and the panel is then washed with an aqueous sodium hydroxide solution while the panel remains wet, thereby preventing the phosphor pixels from falling off, which can occur when the concentration of the oxidizing agent solution is high. As a result, the permissible concentration range of the oxidizing agent solution is expanded, and a stable black matrix type fluorescent film can be obtained.

Agent Masuo Oiwa

Claims (1)

[Claims] (1) A polyvinyl alcohol solution containing dichromate as a photosensitizer is applied onto the panel to form a film, and a shadow mask placed opposite the panel is used to locally expose the film to form the film. to cause a crosslinking reaction, the unexposed unreacted portion of the film is developed and removed, and then,
A light-absorbing substance is applied on the coating and the panel from which the coating has been removed, and the coating in the reaction area and the light-absorbing substance applied thereon are removed with an oxidizing agent solution, after which the panel is wetted. The panel is then cleaned with an aqueous sodium hydroxide solution, a slurry of phosphor particles dispersed in a polyvinyl alcohol photosensitive liquid is applied onto the panel, and exposed through a shadow mask to inject the phosphor into the gaps between the light-absorbing materials. A method for forming a black matrix type fluorescent film characterized by adhering picture elements.