JPH07130291A - Method of forming fluorescent screen - Google Patents

Abstract

PURPOSE:To form a smooth metal-deposited film on a three-color phosphor layer by using aqueous solution, which contains colloidal silica, interface activator, and polyacrylic acid, for a precoating agent. CONSTITUTION:A light absorbing layer 15 and a three-color phosphor layers 18R, 18G, and 18B are formed on the inside of a panel 10 and they are cleaned, and then a precoating agent is applied by spray to fill them between phosphor layers. For the precoating agent, aqueous solution containing colloidal silica, interface activator, and polyacrylic acid is used. The surface of each phosphor layer is smoothed by the precoating agent by rotating the panel 1, where this precoating agent is applied, at specified speed so as to remove the surplus precoating agent by centrifugal force. Next, an organic resin film is made by spraying liquid having acrylic resin for its main ingredients on the precoating agent while rotating the panel 10 and then, drying it. After this, an aluminum- deposited film is formed on the organic resin film by vacuum deposition. Hereby, a smooth metal-deposited film is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphor screen forming method for a color picture tube, and more particularly to a phosphor screen forming method in which a metal vapor deposition film is formed on the back surface of a three-color phosphor layer.

[0002]

2. Description of the Related Art A fluorescent screen of a color picture tube has a panel 1 as shown in FIG. 3 in order to prevent deterioration of the fluorescent material due to collision of a high energy electron beam and to increase the brightness of the screen.
Three-color phosphor layers 2B and 2G formed in a predetermined array on the inner surface of the
, 2R is provided with an aluminum vapor deposition film 3 on the back surface thereof.

In order to prevent the phosphor layers 2B, 2G, and 2R from being contaminated by the vapor-deposited aluminum and to form a smooth film having a high reflection efficiency, the aluminum vapor-deposited film 3 is formed. It is formed by forming a uniformly smooth organic film on the back surface of 2R and vacuum-depositing aluminum on the organic film.

As a method of forming the organic film, in a color picture tube, as shown in FIG. 4 (a), the three-color phosphor layers 2B, 2G, 2R and the light absorbing layer 4 are formed on the inner surface of the panel 1 by a photographic printing method. Then, as a pretreatment for forming an organic film, as shown in (b), the precoat agent 5 is applied by a method such as spraying to form each phosphor layer 2B,
The unevenness on the back surface of 2G and 2R is smoothed, and as shown in (c), an organic resin liquid is sprayed on the precoat agent 5 and dried to form an organic film 6. Table 1 shows an example (conventional example) of a conventional precoat agent.

In order to form a uniformly smooth organic film 5 by this method, the precoat agent 5 applied as a pretreatment is not only filled between the three-color phosphor layers 2B, 2G, 2R. Without, each phosphor layer 2B over the entire surface
, 2G, 2R must be uniformly moistened. That is, the space between the phosphor particles 7B, 7G, 7R forming the three-color phosphor layers 2B, 2G, 2R is the main component of the photosensitizer when the phosphor layers 2B, 2G, 2R are formed by the photo printing method. It is filled with some polyvinyl alcohol 8 (PVA), but it is important that the precoat agent 5 uniformly and sufficiently wets each of the phosphor particles 7B, 7G, 7R and PVA. However, the conventional precoat agent shown in Table 1 is not sufficiently familiar with the three-color phosphor layers 2B, 2G, and 2R, so that the organic resin film 6 formed by coating on the precoat agent 5 becomes uneven. It was difficult to form the organic resin film 6 that was uniformly smooth over the entire surface.

[0006]

As described above, the phosphor screen of the color picture tube has the three-color phosphor layer and the light absorption layer formed on the inner surface of the panel, and then the precoat agent is applied to each phosphor. It is formed by smoothing the unevenness on the back surface of the layer, then applying an organic resin solution on the precoating agent and drying to form an organic resin film, and forming a metal vapor deposition film such as aluminum on the organic resin film. It However, when the phosphor screen is formed by this method, the conventional pre-coating agent is not sufficiently compatible with the three-color phosphor layer and evenly and sufficiently wets each phosphor particle and the polyvinyl alcohol filled between the phosphor particles. Therefore, the organic resin film applied and formed on the precoat agent becomes uneven, and it is not possible to form a uniformly smooth organic resin film over the entire surface, and good metal deposition on the back surface of the three-color phosphor layer. There is a problem that a film cannot be formed.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain a phosphor screen forming method capable of forming a good metal vapor deposition film on the back surface of a three-color phosphor layer. To do.

[0008]

Means for Solving the Problems A three-color phosphor layer having a predetermined arrangement is formed on the inner surface of a panel, a pre-coating agent is applied to the three-color phosphor layer, and then metal deposition is performed on the back surface of the three-color phosphor layer. In the phosphor screen forming method for forming an organic resin film for forming a film, the precoat agent was an aqueous solution containing colloidal silica, a surfactant, and polyacrylic acid.

[0009]

As described above, when the precoating agent is an aqueous solution containing colloidal silica, a surfactant and polyacrylic acid, the wetting action of polyacrylic acid can uniformly and sufficiently wet the three-color phosphor layer. The organic film formed thereafter can be uniformly smoothed over the entire surface.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

First, a light absorbing layer and a three-color phosphor layer are formed on the inner surface of the panel by a photo printing method. That is, FIG. 1 (a)
As shown in FIG. 4, a photosensitizer containing PVA and ammonium dichromate (ADC) as main components is applied to the inner surface of the panel 10 and dried to form a photosensitive film 11, and a shadow having a large number of electron beam passage holes is formed. Exposure is performed through the mask 12, and the pattern of the shadow mask 12 is printed on the photosensitive film 11. Next, the photosensitive film 11 printed with this pattern is developed to remove the unexposed portion, and as shown in FIG.
A resist film 13 corresponding to the pattern of the shadow mask is formed on the inner surface of the. Next, a light absorbing paint is applied to the inner surface of the panel 10 on which the resist film 13 is formed and dried to form a light absorbing paint layer 14 as shown in FIG. Then, the resist film 13 and the light-absorbing coating material applied thereon are peeled off to remove the light-absorbing layer having the three-color phosphor layer forming portion as an exposed portion on the inner surface of the panel 10 as shown in (d). Form 15.

Thereafter, for example, a blue phosphor, PVA, and ADC are formed on the inner surface of the panel 10 on which the light absorption layer 15 is formed.
Is applied and dried to form a phosphor slurry layer 17 as shown in (e), and the phosphor slurry layer 17 is exposed through a shadow mask 12 to expose the phosphor slurry layer 17
The pattern of the shadow mask 12 is printed on. Next, the baked phosphor slurry layer 17 of this pattern is developed to remove the unexposed portion, and as shown in (f), the blue phosphor layer 18B is formed on the blue phosphor layer forming portion of the light absorption layer 15. To form. By repeating the method for forming the blue phosphor layer 18B for the three-color phosphor, as shown in (g), the three-color phosphor layer 18B, 18G and 18R are formed.

In this state, as is apparent from the above-mentioned phosphor layer forming method, the three-color phosphor layers 18B, 18G and 18R.
Is formed by a structure in which PVA hardened by exposure is bound and PVA is filled between the phosphor layers 18B, 18G and 18R.

Next, as shown in FIG.
The light absorption layer and the three-color phosphor layer formed on the inner surface of No. 0 are washed with water (pure water), and a precoat agent is spray-coated to fill each phosphor layer. The panel coated with the precoat agent is rotated (spinning) at 200 to 250 rpm to remove excess precoat agent by centrifugal force, and the surface (back surface) of each phosphor layer is smoothed by the precoat agent.
In this case, the composition of the pre-coating agent to be applied is, as shown in Table 1, an aqueous solution containing colloidal silica, a surfactant and polyacrylic acid in predetermined amounts.

[0015]

[Table 1] Next, while rotating the panel,
A liquid containing an acrylic resin as a main component is spray-coated on the pre-coating agent applied on the color phosphor layer and dried to form an organic resin film. At this time, the pre-coating agent applied to the lower part is also dried at the same time. Then, an aluminum vapor deposition film is formed on the organic resin film by vacuum vapor deposition.

By the way, when the phosphor screen is formed by the above method, polyacrylic acid is a liquid polymer of acrylic acid and methacrylic acid, which is contained in the precoat agent applied as a pretreatment for forming the organic resin film. Due to the wetting action of polyacrylic acid, three-color phosphor layers 18B, 1
8G and 18R can be evenly and sufficiently moistened,
The organic film formed thereafter can be uniformly smoothed over the entire surface. As a result, by vacuum-depositing aluminum on this organic film, a smooth aluminum vapor-deposited film can be formed on the back surfaces of the three-color phosphor layers 18B, 18G, 18R.

[0017]

The pre-coating agent applied to the three-color phosphor layer as a pretreatment for forming the organic resin film for forming the metal deposition film on the back surface of the three-color phosphor layer is colloidal silica, a surfactant, or When the aqueous solution containing acrylic acid is used, the three-color phosphor layer can be uniformly and sufficiently wetted by the wetting action of polyacrylic acid, and the organic film to be formed thereafter is uniformly smoothed over the entire surface. You can As a result, a smooth metal vapor deposition film can be formed on the back surface of the three-color phosphor layer through this organic resin film.

[Brief description of drawings]

1A to 1G are views for explaining a method of forming a light absorption layer and a phosphor layer on a phosphor screen, respectively.

FIG. 2 is a diagram showing a process of forming an aluminum vapor deposition film on the back surfaces of the light absorption layer and the phosphor layer.

FIG. 3 is a view showing a structure of a phosphor screen having an aluminum vapor deposition film formed on the back surface of a three-color phosphor layer.

FIG. 4A to FIG. 4C are views for explaining problems in the conventional phosphor screen forming method.

[Explanation of symbols]

 10 ... Panel 15 ... Light absorption layer 18B, 18G, 18R ... Tricolor phosphor layer

Claims (1)

[Claims] 1. A three-color phosphor layer having a predetermined arrangement is formed on an inner surface of a panel, a pre-coating agent is applied to the three-color phosphor layer, and then a metal deposition film is formed on the back surface of the three-color phosphor layer. In the method for forming a phosphor screen for forming an organic resin film for achieving the above, the precoat agent is an aqueous solution containing colloidal silica, a surfactant and polyacrylic acid.