JPS63102139A - Manufacture of fluorescent screen of cathode-ray tube - Google Patents

Abstract

PURPOSE:To simplify processes and to improve stability in manufacturing yield and quality by sticking a phosphor film on a surface of a face plate and forming a metallic film on this phosphor film by pressure adhesion and thermal decomposition of adhesives or the like. CONSTITUTION:After a phosphor film 14 is formed on an inner surface of a face plate 20, a transcribing film 15 with the same size as the inner surface is placed thereon. The film 15 is formed by coating a base film 10 with a parting agent layer 11 and piling an aluminium film 12 on it by vacuum evaporation and besides piling a thermoplastic adhesive-coated layer 13 thereon. The film 14 and the layer 13 are made to touch each other and pressed by a heated pressing metallic mold 30. Next the film 10 is peeled, and the adhesive coating between the films 12 and 14 and the parting agent sticked on the other surface of the film 12 are heated to be thermally decomposed, and so a metallic film is formed on the phosphor film. Hence, processes can be simplified and stability in manufacturing yield and quality can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a cathode ray tube, and particularly to a method for manufacturing a phosphor screen thereof.

(Prior Art) Generally, the phosphor screen of a cathode ray tube consists of a phosphor layer formed on a face plate, an aluminum metal back layer (
metal film) is formed. This metal back layer is electrically conductive and has the effect of reflecting light emitted from the phosphor toward the face plate to improve brightness, and is required to have high reflectance characteristics. In addition, the metal back layer is usually formed through many steps, for example,
First, a thin film of water is made on the phosphor layer deposited on the inner surface of the faceplate, and then a lacquer is sprayed on top of it to form a thin film using the non-aqueous property.Next, ammonium oxalate After spraying the solution, remove the excess, dry, and apply a high vacuum. Then, aluminum is deposited on the lacquer film, and finally, the organic matter in the lacquer film is burned off to complete the process.

(Problems to be Solved by the Invention) Such conventional techniques first require the use of large amounts of highly flammable materials such as acetone and toluene, and the long time it takes to create a high vacuum. There are problems in that a large amount of capital investment is required and it takes time. Second, the film forming process in particular is extremely delicate, and even slight changes in materials or conditions can cause defects such as a decrease in brightness or blistering of the metal back film, resulting in a decline in yield and quality. There is a problem.

An object of the present invention is to provide a method for manufacturing a phosphor screen for a cathode ray tube with stable workability and performance by shortening the process without requiring a large capital investment.

[Structure of the invention]

(Means for Solving the Problems) The present invention consists of a first step of adhering and forming a fluorescent film on the surface of a face plate, a second step of pressing and adhering a gold rA crotch onto the fluorescent film, and a second step of adhering the fluorescent film to the surface of the face plate. This method of manufacturing a phosphor screen of a cathode ray tube includes a third step of heating a face plate to which a film and a metal film are attached, and forms a metal film on a phosphor film.

Second. In the process, a transfer film in which an adhesive layer, a metal film, a release agent layer, and a base film are laminated in this order is pressure-bonded onto the fluorescent film so that the adhesive layer side is in contact with the fluorescent film, and then the base film is attached. The metal film can be peeled off and adhered onto the fluorescent film.

In the third step, the adhesive layer and release agent layer of the transfer film adhered onto the fluorescent film can be thermally decomposed.

In the second step, the transfer film on the fluorescent film can be pressed while being heated.

The adhesive layer is a thermoplastic adhesive, and the metal film is a thermoplastic adhesive.

It can be an aluminum film.

In the second step, the heating temperature can be 100 to 300°C.

Pressure force is 1 kg/cm2 to 3000 kg/cm2
It can be done.

(Function) In the present application, when forming a metal film, it is possible to form a metal film on the fluorescent film by adhering the metal film on the fluorescent film by pressing and then thermally decomposing the adhesive. water, like
There is no need to handle liquids such as organic solvents, there is no need for time-consuming processes such as filming or vacuum evaporation of aluminum, and the process can be completed in -1 press operations.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 to 4 show the face plate (20) of a color cathode ray tube. Figure 1 is a sectional view of the face plate, and Figures 2 to Φ are partially enlarged views of the phosphor screen. It explains the manufacturing type.

First, as shown in Figure 1, the face plate (20)
After forming a fluorescent film (14) on the inner surface of the face plate (14) by, for example, a photographic exposure method, a face plate (14) is formed on the fluorescent film (14).
20) Place a transfer film (15) of approximately the same size as the inner surface and press it with a mold (3o).

As shown in an enlarged view in FIG. 2, this transfer film (15) is coated with a mold release agent on a base film (10) made of polyester or the like. (11), an aluminum layer (12) and an adhesive layer (13) are laminated in this order. This transfer film (15) is a polyester base film (10
), apply a mold release agent to the mold release agent layer (11), and apply approximately 1.
It can be easily and inexpensively made by vacuum-depositing aluminum to a thickness of 1,000 mm and applying a thermoplastic adhesive made of polyvinyl acetate thereon. This transfer film (15) is attached to the inner surface of the face plate (20) of a 20-inch color cathode ray tube, which has a fluorescent film that emits light in three colors of blue, green, and red, that is, the fluorescent film (14).
Place the phosphor and thermoplastic adhesive on top so that they are in contact with each other.
As shown in Figs. 1 and 2, a press mold (30
) with a pressure of approximately 200 kg/cm2.
Next, as shown in FIG. 3, the base film (10) of the transfer film (15) is peeled off. During this time, in a short period of about 15 seconds, the release agent layer (11) attached to the other surface of (12) is removed in the subsequent manufacturing process of the color cathode ray tube.
The material is thermally decomposed by heating at about 400"C to 450C to produce a phosphor screen as shown in FIG. 4, which is then completed as a color cathode ray tube through commonly known processes.

In order to manufacture a phosphor screen using this manufacturing method, conventionally it took 20 minutes to 40 minutes for filming and aluminum vacuum deposition.
The press operation, which previously took several minutes, can be completed in several tens of seconds, resulting in a significant reduction in equipment investment.

In this embodiment as well, in order to make a transfer film, a step of vapor depositing aluminum on this film is required, whereas in the past, the process had to be performed for each face plate.

It is much more efficient if done continuously over a long film;
Also, there is little variation in quality.

Furthermore, since there is no need to handle liquids such as water and organic solvents, it is extremely easy to control conditions, and there is an advantage that both yield and quality stability are improved.

In this way, according to the color cathode ray tube that was manufactured through the normal process, a stable improvement in brightness of about 10% was observed, even though the operations above 8 were carried out in a particularly strict room without air conditioning. Despite this, there were no defects such as blistering of the aluminum film or adhesion of dust, and a good yield was achieved.

Thermoplastic adhesives suitable for this example include polyvinyl acetate, copolymers of polyvinyl acetate and acrylic esters or ethylene, ethyl acrylate/butyl acrylate, methacrylic esters of these, styrene, acrylonitrile, etc. copolymers with polyethylene, copolymers of this with ethylene or vinyl acetate, gelato polymerization of unsaturated acids such as acrylic acid, polyamides, and polysaccharides with a thickness of less than 0.1% will result in insufficient adhesive strength. If it exceeds 50, it is within a practical range for aluminum during pyrolysis of adhesives, etc., but the optimum value must be found in consideration of the acceleration voltage of the cathode ray tube used.

The surface of the press mold must have a curved surface that follows the curved surface of the inner surface of the face plate, and must be made of a material with appropriate elasticity in order to uniformly press against the fluorescent film, which has several to several tens of concavities and convexities. For example, rubber is necessary. The press pressure is preferably from 1 kg/cd to 3000 kg/cm2; if it is lower than this, uniform adhesion will not be achieved, and if it is higher than this, the thickness of the aluminum at the convex portions will become thinner, resulting in a decrease in brightness.

The temperature of the mold surface varies depending on the adhesive used, but it is approximately 10
0 to 300°C is preferred.

Note that the transfer film may further include a protective layer between the mold release agent and the aluminum film in order to protect the aluminum film.

〔Effect of the invention〕

As described above, according to the present invention, the process can be simplified and the yield and quality stability of finished products can be improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view for explaining one embodiment of the present invention, and FIGS. 2 to 4 are cross-sectional views for explaining the manufacturing method according to the present invention. 10...Base film, 11...Mold release agent layer 1
2... Aluminum prisoner, 13... Adhesive layer 14
... Fluorescent film, 15... Transfer film 2
0...Face plate, 30...Mold agent Patent attorney Noriyoshi Chika Body direction Norio Ogo Figure 1 Figure 2

Claims (8)

[Claims] (1) A first step of adhering and forming a fluorescent film on the surface of a face plate, a second step of pressing and bonding a metal film on the fluorescent film, and a face plate to which the fluorescent film and metal film are attached. A method for manufacturing a phosphor screen of a cathode ray tube, comprising a third step of heating the phosphor, and forming a metal film on the phosphor film. (2) The second step is to press and bond the transfer film, which is laminated in the order of adhesive layer, metal film, release agent layer, and base film, onto the fluorescent film so that the adhesive layer side is in contact with the fluorescent film. 2. The method of manufacturing a phosphor screen of a cathode ray tube according to claim 1, further comprising peeling off said base film. (3) A method for manufacturing a phosphor screen for a cathode ray tube according to claim 1, characterized in that a mold is used to press the metal film onto the phosphor film. (4) The fluorescence of the cathode ray tube according to claim 1, wherein the third step is to thermally decompose the adhesive layer and the release agent layer of the transfer film bonded onto the fluorescent film. Surface manufacturing method. (5) The method for manufacturing a phosphor screen of a cathode ray tube according to claim 2, wherein in the second step, the transfer film on the phosphor film is pressed while being heated. (6) The adhesive layer is a thermoplastic adhesive, and the metal film is
3. The method for manufacturing a phosphor screen of a cathode ray tube according to claim 2, wherein the phosphor screen is an aluminum film. (7) In the second step, the heating temperature is 100 to 30
5. The method for manufacturing a phosphor screen of a cathode ray tube according to claim 4, wherein the temperature is 0°C. (8) Pressure force is 1kg/cm^2~3000kg/c
3. The method for manufacturing a phosphor screen of a cathode ray tube according to claim 2, wherein the phosphor screen is m^2.