JPH0532856B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for easily and efficiently forming a fluorescent film and a conductive film on a glass substrate, particularly on a face plate of a cathode ray tube, and a transfer material used in the method.

[Conventional technology]

Conventionally, a slurry coating exposure method, a sedimentation method, and the like have been used to form a fluorescent film on the face plate of a cathode ray tube. Furthermore, methods for forming the conductive film include a slurry coating exposure method and a vapor deposition method. This conductive film is formed of conductive carbon or the like between the fluorescent film and the face plate in order to enhance the contrast of the image and obtain a dense and uniform screen.
Furthermore, by forming a conductive film, it becomes easy to establish electrical conduction with the anode button through a contact duck.

[Problem to be solved by the invention]

By the way, in the slurry coating exposure method for forming the fluorescent film described above, a slurry in which a fluorescent material is dispersed in a photosensitive resin made of, for example, polyvinyl alcohol and ammonium dichromate is spin coated onto a face plate, dried, and exposed to ultraviolet rays. to expose the desired pattern. This is followed by development with water to remove unexposed areas and form a fluorescent film. Further, the slurry coating exposure method for forming the conductive film is a method in which carbon slurry is spin coated and dried. Therefore, when a fluorescent film and a conductive film are formed by a slurry coating exposure method, there are drawbacks such as a large number of steps, a complicated apparatus, and a lack of productivity. In addition, in the method of forming a fluorescent film using the sedimentation method, the phosphor is precipitated onto the face plate in a suspension containing the phosphor and a binder (water glass, etc.), and then the supernatant liquid is gently poured off. In this method, a fluorescent film is formed. Therefore, there are disadvantages in that it takes time to precipitate the phosphor and it is difficult to form a predetermined pattern. Furthermore, the vapor deposition method, which is another method for forming a conductive film, also has the disadvantage that maintenance of the equipment is troublesome. The purpose of the present invention is to solve the above-mentioned problems and to provide a method for forming a fluorescent film and a conductive film, which can easily and efficiently form a fluorescent film and a conductive film on a glass substrate, especially on the face plate of a cathode ray tube. An object of the present invention is to provide a transfer material used in the method.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured as follows by applying a transfer method. That is,
In the phosphor film forming method of the present invention, a phosphor layer containing a phosphor and a binder, and a conductive layer containing conductive carbon, glass frit, and a binder and provided on the phosphor layer constitute a transfer layer. Using a transfer material formed on a base film exhibiting peelability as a layer, the transfer layer is transferred onto a glass substrate, and then baked at a temperature equal to or higher than the melting temperature of the glass frit to separate the phosphor layer and the conductor layer. A fluorescent film and a conductive film obtained by removing the respective binders were formed on the glass substrate. Further, the transfer material for forming a fluorescent film of the present invention transfers a fluorescent layer containing a fluorescent substance and a binder, and a conductive layer provided on the fluorescent layer containing conductive carbon, glass frit, and a binder. It was constructed so that it was provided on a base film exhibiting releasability as one of the constituent layers. Hereinafter, the present invention will be described in more detail with reference to the drawings, taking as an example a case in which a fluorescent film and a conductive film are formed on the face plate of a cathode ray tube. 1 to 3 are cross-sectional views showing one embodiment of the transfer material used in the present invention. FIG. 4 is a sectional view showing the transfer process. 1 is a base film, 2 is a release layer, 3 is a transfer layer, 4 is a conductor layer, 5 is a phosphor layer,
Reference numeral 6 indicates an adhesive layer, 7 indicates a transfer material, and 8 indicates a face plate. As the base film 1, plastic films such as polyethylene terephthalate, polypropylene, polyethylene, nylon, cellophane, etc.
Alternatively, a composite film of these materials and paper, which is used as a base film for ordinary transfer materials, may be used. In order to impart releasability to the base film 1, the base film 1 may be coated with silicone or wax, or a release layer 2 may be provided. For the release layer 2, thermoplastic resin, natural rubber, synthetic rubber, etc. are used, and gravure printing method,
It is formed by ordinary printing methods such as screen printing and roll coating. As the phosphor layer 5, ZnS:Ag, SnS:Cu,
Phosphors conventionally used in cathode ray tubes, such as Al, Y ₂ O ₂ S:Eu, are used, and ink is used with a thermoplastic resin or the like as a binder. As a method for forming the phosphor layer 5, in consideration of the required film thickness and the particle size of the phosphor, it is desirable to print by screen printing. Since the phosphor layer 5 is formed on the base film 1 or the release layer 2, which has excellent smoothness, the surface on the base film 1 side has excellent smoothness. The phosphor layer 5 is formed according to the shape of the screen. When used in a color cathode ray tube, the phosphor layer 5 may be formed by regularly arranging phosphors of three colors, red, blue, and green, in a stripe or dot shape so that they do not come into contact with each other. As the conductor layer 4, a conductive ink is used in which a thermoplastic resin or the like is used as a binder and conductive carbon is dispersed together with glass frit. The weight ratio of conductive carbon to glass frit is 8.0:
2.0-0.5: 9.5 is appropriate. Particularly preferably,
It is recommended to set it to 7.0:3.0 to 4.0:6.0. If the ratio of conductive carbon is higher than 8.0:2.0, the adhesion between the conductor layer 4 and the face plate 8 will be small, so when providing a terminal on the conductor layer 4 to establish electrical continuity with the anode button after firing, The conductor layer 4 falls off.
Furthermore, if the ratio of glass frit is higher than 0.5:9.5, the electrical resistance will be high and no conduction will occur even if the anode button is electrically connected after firing. Table 1 shows an example of the relationship between the weight ratio of conductive carbon and glass frit in the conductive layer and the characteristics of the transfer material.
Shown below.

[Table] ◎...Very good ○...Good ×...Not good The weight ratio of the conductive carbon and glass frit to the binder is suitably 8.6:1.4 to 1.6:8.4. If the binder ratio is less than 8.6:1.4,
At the time of transfer, the conductor layer 4 cannot be maintained as a layer, and intralayer breakdown occurs. Furthermore, if the ratio of the binder is greater than 1.6:8.4, the density of the conductor layer 4 will be low and conductivity will be lost after firing. Since the conductor layer 4 is used in a so-called flat type rear-viewing cathode ray tube, it is formed between the phosphor layer 5 and the adhesive layer 6 (see FIG. 1). As a method for forming the conductor layer 4, it is preferable to print by screen printing in consideration of the required film thickness and the particle size of the conductor and glass frit. Further, the shape of the conductor layer 4 is such that the phosphor layer 5
The conductor layer 14 that does not contain glass frit may be used in the portion laminated with the anode button, and the conductor layer 4 containing glass frit may be formed only in the portion where a terminal for conducting with the anode button is provided (see Fig. 2). ). By doing so, the portion of the conductor layer 4 that contains the glass frit has a strong adhesive force with the face plate 8, and can be made to conduct well with the anode button, while the portion of the conductor layer 14 that does not contain the glass frit The unevenness caused by the presence of glass frit is eliminated, and the smoothness of the surface of the fluorescent film after transfer is not adversely affected. Furthermore, as another shape of the conductor layer 4, a conductor layer 14 not containing glass frit is first formed on the phosphor layer 5, and then a conductor layer 4 containing glass frit is formed on top of the conductor layer 14. Good (3rd
(see figure). In this case, reduce the weight ratio of the glass frit dispersed in the conductor layer 4 or reduce the particle size of the glass frit to prevent the unevenness caused by the glass frit from adversely affecting the smoothness of the surface of the phosphor film. Good. The adhesive layer 6 is preferably a heat-sensitive and pressure-sensitive adhesive layer using a resin such as polyamide that has good adhesiveness to the glass material used for the face plate of the cathode ray tube. As a method for forming the film, a conventional printing method such as a gravure printing method, a screen printing method, or a roll coating method may be used. Using the transfer material 7 having the layered structure described above, a fluorescent film and a conductive film are formed on the face plate 8 of the cathode ray tube. First, the transfer material 7 is placed on the face plate 8 and heated and pressed to fuse the adhesive layer 6 to the face plate 8. The temperature at this time is 130~
A temperature of 230° C. and a pressure of 3 to 150 Kg/cm ² are appropriate. Next, when the base film 1 is peeled off, only the base film 1 of the transfer material 7 is peeled off, and the transfer layers 3 such as the adhesive layer 6, the conductor layer 4, and the phosphor layer 5 are transferred onto the face plate 8. (See Figure 4). The surface of the phosphor layer 5 has excellent smoothness due to the base film 1 or the release layer 2. Next, the face plate 8 is fired at 300 to 400°C, which is the melting point of the glass frit, to remove organic components other than the phosphor and the conductor, and to fuse the glass frit so that it becomes a link between the conductive carbon and the face plate. By doing so, the fluorescent film and conductive film are completed.

【Example】

Example 1 A release layer with a thickness of 1 μm was provided on a polyester film with a thickness of 25 μm using the gravure printing method using an ink consisting of the following composition 1, and then a screen was applied on top of the release layer using an ink consisting of composition 2. A phosphor layer with a thickness of 30 μm is provided by a printing method, and composition 3 is applied on top of it.
A conductor layer containing glass frit with a thickness of 25 μm was formed by screen printing using an ink consisting of the following. Furthermore, an adhesive layer having a thickness of 5 μm was provided by screen printing using an ink having composition 4 so as to cover the entire surfaces of the phosphor layer and the conductor layer, thereby obtaining a transfer material (see FIG. 1). Composition 1 (parts by weight) Acrylic resin 10 Toluene 45 Methyl ethyl ketone 45 Composition 2 (parts by weight) Acrylic resin 20 Phosphor powder (Y ₂ O ₂ S: Eu) 20 Isophorone 10 Cyclohexanone 50 Composition 3 (parts by weight) Acrylic resin 35 Conductive carbon powder 21 Glass frit (boric acid-silicate glass) 9 Isophorone 10 Cyclohexanone 25 Composition 4 (Parts by weight) Polyamide resin 30 Ethyl cellosolve 30 Cyclohexanone 40 The transfer material thus obtained was placed on a face plate at 150°C. , 5Kg/ ^cm2 , then 450℃
The organic components on the face plate were removed by baking for 30 minutes, and a fluorescent film and a conductive film were formed on the face plate. Example 2 A release layer and a phosphor layer were provided on a 25 μm thick polyester film in the same manner as in Example 1. A conductor layer containing no glass frit was formed thereon with a thickness of 30 μm by screen printing using an ink having composition 5. Next, a conductor layer containing glass frit having a thickness of 25 μm was provided on the conductor layer in a portion not overlapping the phosphor layer by screen printing using an ink having composition 6. Furthermore, an adhesive layer with a thickness of 5 μm was provided by screen printing using an ink having composition 4 so as to cover the entire surface of the phosphor layer and each conductor layer.
A transfer material was obtained (see Figure 2). Composition 5 (parts by weight) Acrylic resin 35 Conductive carbon powder 35 Isophorone 10 Cyclohexanone 20 Composition 6 (parts by weight) Acrylic resin 35 Conductive carbon powder 6 Glass frit (boric acid-silicate glass) 24 Isophorone 10 Cyclohexanone 25 Like this The resulting transfer material was transferred onto a face plate at 150℃ and 5Kg/ ^cm2 , and then at 450℃.
The organic components on the face plate were removed by baking for 30 minutes, and a fluorescent film and a conductive film were formed on the face plate. Example 3 A release layer, a phosphor layer, and a conductive layer containing no glass frit were provided on a 25 μm thick polyester film in the same manner as in Example 2. Next, an ink having a composition of 7 is applied to the part overlapping with this conductive layer using a screen printing method to thicken the film.
A conductor layer containing a 25 μm glass frit was provided. Composition 7 (Parts by weight) Acrylic resin 35 Conductive carbon powder 12 Glass frit (boric acid-silicate glass) 18 Isophorone 10 Cyclohexanone 25 Furthermore, ink consisting of composition 4 was used to cover the entire surface of the phosphor layer and conductor layer. An adhesive layer with a thickness of 5 μm was provided using a screen printing method to obtain a transfer material (see Figure 4). The thus obtained transfer material was transferred onto a face plate in the same manner as in Example 1, and baked to form a fluorescent film and a conductive film on the face plate.

【Effect of the invention】

In the method for forming a phosphor film of the present invention, a phosphor layer containing a phosphor and a binder, and a conductive layer provided on the phosphor layer containing conductive carbon, glass frit, and a binder constitute a transfer layer. Using a transfer material formed on a base film exhibiting peelability as a layer, the transfer layer is transferred onto a glass substrate, and then baked at a temperature equal to or higher than the melting temperature of the glass frit to separate the phosphor layer and the conductor layer. A fluorescent film and a conductive film obtained by removing the respective binders are formed on the glass substrate. Therefore, it has the following excellent effects. (1) The fluorescent film and conductive film are formed as a transfer layer of one transfer material, and they can be simultaneously formed on the glass substrate by transfer, making it easy, efficient, and suitable for mass production. . (2) Since the fluorescent film and the conductive film can be formed on a removable base film by printing, there is no variation in film thickness due to work, and the fluorescent film can reproduce the surface of the base film. This results in a surface with excellent smoothness and stable quality. Further, the transfer material for forming a fluorescent film of the present invention transfers a fluorescent layer containing a fluorescent substance and a binder, and a conductive layer provided on the fluorescent layer containing conductive carbon, glass frit, and a binder. It is constructed so that it is provided on a base film exhibiting releasability as one of the constituent layers. Therefore, it has the following excellent effects. (1) The fluorescent film and the conductive film can be formed on a removable base film by printing, which is simple, efficient, and suitable for mass production. (2) Since the fluorescent film and conductive film can be formed by printing, the size and shape of the fluorescent screen can be freely selected.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views showing one embodiment of the transfer material of the present invention. FIG. 4 is a sectional view showing the transfer process. 1...Base film, 2...Peeling layer, 3...
Transfer layer, 4, 14... Conductor layer, 5... Fluorescent layer, 6... Adhesive layer, 7... Transfer material, 8... Face plate.

Claims (1)

[Scope of Claims] 1. A phosphor layer containing a phosphor and a binder, and a conductive layer containing conductive carbon, glass frit, and a binder and provided on the phosphor layer as one constituent layer of a transfer layer. Using a transfer material formed on a base film exhibiting peelability, the transfer layer is transferred onto a glass substrate, and then baked at a temperature higher than the melting temperature of the glass frit to separate each of the phosphor layer and the conductor layer. A method for forming a fluorescent film, comprising forming a fluorescent film and a conductive film obtained by removing the binder on the glass substrate. 2. A base film that exhibits removability, with a phosphor layer containing a phosphor and a binder, and a conductive layer provided on the phosphor layer containing conductive carbon, glass frit, and a binder as one constituent layer of a transfer layer. A transfer material for forming a fluorescent film, comprising: a transfer material for forming a fluorescent film; 3. Claim 2, wherein the weight ratio of the conductive carbon to the glass frit in the conductive layer is 8.0:2.0 to 0.5:9.5.
The described transfer material for forming a fluorescent film. 4 The weight ratio of the conductive carbon and glass frit of the conductive layer to the binder is 8.6:1.4 to 1.6:
8.4. The transfer material for forming a fluorescent film according to claim 2.