JPS6247342B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for manufacturing a cathode ray tube using a printing method, and particularly to a method for easily obtaining a fluorescent surface with high brightness.

Regarding the production of a fluorescent surface for a cathode ray tube, the present inventors have previously proposed a production method using a printing method.
This method applies red to the entire side of the face plate 1 for black and white use, and red to one side of the face plate 1 for color use as shown in Figure 1.
The fluorescent film layer 2 that emits green and blue fluorescent colors is formed into a dot-like, matrix-like, striped-like pattern, etc., by employing a method such as a screen printing method, a tacho printing method, or a gravure offset printing method. , to form. In many cases, a light absorption layer 3 is interposed between the fluorescent film layers 2 to partition each fluorescent film layer. After forming the fluorescent film layer 2,
A metal back layer 4 for brightening the image by reflecting the emitted color in the viewing direction is formed by means such as vacuum deposition, and then baked at 400 to 500°C to be included in the fluorescent film layer 2. Removed unnecessary organic matter.

The production of a fluorescent surface using such a printing method is
It has the advantage of being able to significantly shorten the process and is suitable for low-cost mass production, and is therefore expected to be used. However, the fluorescent surfaces obtained by this method sometimes lack luminance, and the present invention is the result of identifying the cause of this problem and making improvements.

In order to obtain sufficient luminance, it is important that the reflective surface of the metal back layer is a mirror surface, not only for fluorescent films produced by printing methods but also for fluorescent films produced by conventional exposure methods. For this purpose, it is extremely important that the top surface of the phosphor film be smooth before the metal back layer is deposited. Even in production using the conventional exposure method, in order to obtain a high-brightness fluorescent surface, so-called filming (intermediate film creation process) is performed on the fluorescent film layer using a lacquer before forming the metal back layer. However, this filming process was very complicated, and the process itself had a high defect rate, leading to an increase in manufacturing costs. For fluorescent surfaces with low brightness, the desired brightness can be obtained by increasing the intensity of the electron beam, but this increases power consumption and is uneconomical.

The present invention eliminates the above-mentioned drawbacks and provides a method for easily obtaining a high-brightness fluorescent surface without performing a filming process. The present invention will be explained in detail below.

Generally, the printed ink film is torn off from the plate (or from the transfer body in the case of offset printing) onto the printing medium. This also applies to the present invention, and therefore, as shown in FIG. 2, the surface of the phosphor layer 5 immediately after being formed on the face plate 1 by the printing method is rough. If the fluorescent film layer is solidified in this state to form a metal back layer, the reflective surface of the metal back layer will not be a mirror surface, and only a fluorescent surface with low brightness can be produced. Note that 6 in the figure is a light absorption layer.

Therefore, in the present invention, a surfactant is added to the ink containing the phosphor powder 7 as a main component to lower the surface tension of the ink, or a plasticizer or the like which hardly evaporates at room temperature is added to the ink to improve the ink. To prevent drying, or for the same purpose, add a slow-drying solvent to suppress the increase in viscosity caused by drying, keep the ink in a fluid state, and leave it for a certain period of time. This makes it possible to obtain a fluorescent film layer 5 having a smooth surface.

Further, as shown in FIG. 3, the phosphor powder 7 generally has a specific gravity of 4 or more and is heavy, so if it is left for a certain period of time for smoothing, the phosphor powder 7 will settle in the ink vehicle 8. Since the surface of the fluorescent film layer 5 becomes smooth and glossy, the surface of the fluorescent film layer 5 becomes smooth and glossy. If a metal back layer 4 is applied to such a smooth fluorescent film layer 5 as shown in FIG. 1, a metal back layer with high reflection efficiency can be obtained, and a cathode ray tube fluorescent surface with high luminance can be produced. can.

Here, as the surfactant, one that is compatible with the ink vehicle may be selected.
A metal-free surfactant, that is, a nonionic surfactant is preferable so as not to impair the luminescent properties of the phosphor, but an ionic surfactant may also be sufficient. The equivalent time of leaving for smoothing depends on the drying speed of the ink and the type and amount of additives added to the ink, but it is difficult to obtain a smooth film unless it is left for more than 5 minutes. As for the drying method of the ink vehicle, it is necessary that the ink does not set within 5 minutes, so it is preferable to use an ultraviolet curing type, an electron beam curing type, or an oxidative polymerization type.If the ink vehicle is a solvent evaporation drying type, a slow-drying solvent should be used or It is necessary to use a plasticizer together.

In addition, for the fluorescent ink used, at least one of acrylic resin, polyester resin, and salt-vinyl acetate resin is selected for the resin content so that "blisters" or "cracks" do not occur on the surface of the metal bag during baking after the metal bag is baked. , phosphor content is 15-90% by volume,
It is desirable that the content be as high as 20 to 70% by volume.

As described above, according to the present invention, a fluorescent surface of a cathode ray tube with high brightness can be obtained very easily, there is no need for filming, and power consumption can be reduced. This makes it possible to almost eliminate defective products and reduce manufacturing costs.

Examples will be described below.

Example 1 A fluorescent ink containing a surfactant according to the present invention having the following composition was printed by gravure offset printing on a face plate on which a light-absorbing film had already been formed.

Green phosphor powder product name P22-GN4 (manufactured by Dainippon Toyo Co., Ltd.) 70.0% by weight Acrylic-polyester resin product name NK Ester A-TMM-3 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) 26.9 〃 Benzophenone 1.5 〃 Triethanolamine 0.6 〃 2-Ethylhexyl acrylate (plasticizer)
1.0 〃 Blue phosphor powder product name P22-B1 (manufactured by Dainippon Toyo Co., Ltd.) 70.0% by weight NK ester A-TMM-3 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) 26.9 〃 Benzophenone 1.5 〃 Triethanolamine 0.6 Weight% 2-ethylhexyl acrylate 1.0 〃 Red fluorescent powder product name P22-RE3 (manufactured by Dainippon Toyo Co., Ltd.) 70.0% by weight NK Ester A-TMM-3 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) 26.9 〃 Benzophenone 1.5 〃 Triethanolamine 0.6 〃 2-Ethylhexyl acrylate 1.0 〃 At this time, after each color printing is completed, leave it for about 6 hours so that the printed film has a mirror surface, then irradiate the ink with ultraviolet rays, and then apply the next color. I did some color printing. Next, apply a metal back of approximately 1500Å, approximately 470Å
C. and used 2-ethylhexyl acrylate as a plasticizer to prepare a fluorescent surface for a cathode ray tube.

Immediately after printing with the ink of the above composition, the ink was exposed to ultraviolet light to set the ink, and a metal back was applied in the same manner, followed by firing to produce a fluorescent surface as a comparative example.

The inventive example had about 1.9 times the brightness as the comparative example, and a highly bright fluorescent surface could be obtained without filming.

Example 2 A phosphor ink having the following composition was used to print Green,
Blue and red phosphors were printed using a screen printing method.

Green P22-GN4 (manufactured by Dainippon Toyo Co., Ltd.) 50.0% by weight Acrylic resin product name Dianal BR-75 (manufactured by Mitsubishi Rayon Co., Ltd.)
25.0 〃 Butyl Cellosolve 24.5 〃 Surfactant Dia-Aid AD-9001 (manufactured by Mitsubishi Rayon Co., Ltd.) 0.5 〃 Blue P22-B1 (manufactured by Dainippon Toyo Co., Ltd.) 50.0% by weight Dianal BR-75 (manufactured by Mitsubishi Rayon Co., Ltd.) made)
25.0 〃 Butyl cellosolve 24.5% by weight Diamond Aid AD-9001 (manufactured by Mitsubishi Rayon Co., Ltd.) 0.5 〃 Red P22-RE3 (manufactured by Dainippon Toyo Co., Ltd.) 50.0% by weight Dianal BR-75 (manufactured by Mitsubishi Rayon Co., Ltd.)
25.0 〃 Butyl Cellosolve 24.5 〃 Diamond Aid AD-9001 (manufactured by Mitsubishi Rayon Co., Ltd.) 0.5 〃 At this time, leave it for 30 minutes after printing one color, then set the ink at 100℃ for 20 minutes, and print the next color. I did this. Next, an aluminum bag of about 1500 Å was applied and fired at about 470°C to produce a fluorescent surface of a color cathode ray tube according to the present invention.

Next, green, blue, and red phosphors were printed by screen printing using a quick-drying solvent from the above example and a phosphor ink with the following composition that does not contain the surfactant Diamond Aid AD-9001. .

Green P22-GN4 (manufactured by Dainippon Toyo Co., Ltd.) 50.0% by weight Dianal BR-75 (manufactured by Mitsubishi Rayon Co., Ltd.)
25.0% by weight Ethyl Cellosolve 25.0 〃 Blue P22-B1 (manufactured by Dainippon Toyo Co., Ltd.) 50.0% by weight Dianal BR-75 (manufactured by Mitsubishi Rayon Co., Ltd.)
25.0 Ethyl cellosolve 25.0 Red P22-RE3 (manufactured by Dainippon Toyo Co., Ltd.) 50.0% by weight Dianal BR-75 (manufactured by Mitsubishi Rayon Co., Ltd.)
25.0 〃 Ethyl cellosolve 25.0 〃 In this case, immediately after printing one color, the ink was set at 100°C for 30 minutes, and the next color was printed.

Next, as in the example of the present invention described above, a metal bag,
Firing was performed to produce a fluorescent surface as a comparative example.

The inventive example had about 1.8 times the brightness as the comparative example, and a very bright fluorescent surface could be obtained without filming.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the fluorescent surface of a cathode ray tube, FIG. 2 is a cross-sectional view of the fluorescent surface immediately after printing, and FIG. 3 is a cross-sectional view of the fluorescent surface after a considerable period of time has elapsed according to the present invention. DESCRIPTION OF SYMBOLS 1... Face plate, 2, 5... Fluorescent film layer, 3, 6... Light absorption layer, 4... Metal back layer, 7... Fluorescent powder, 8... Vehicle.

Claims (1)

[Claims] 1. A step of applying ink containing phosphor powder as a main component onto the face plate by a printing method to form a fluorescent film layer, and a step of forming a metal back layer covering the entire surface of the fluorescent film layer. A method for producing a fluorescent surface for a cathode ray tube, which comprises adding at least one of a surfactant, a plasticizer, and a slow-drying solvent to the ink, and leaving the ink for a considerable period of time after printing until it solidifies. A method for producing a fluorescent surface of a cathode ray tube, comprising: smoothing the upper surface of the fluorescent film layer, and then forming a metal back layer.