JPH05347125A - Method for making fluorescent screen for cathode-ray tube and manufacture of index tube - Google Patents

Abstract

PURPOSE:To eliminate a resultant failure without requiring a protective film and at the same time to shorten a manufacturing process by bringing a photosensitive agent containing fluorescent slurry into non-chrome to eliminate the damage on carbon stripes to be formed. CONSTITUTION:After cleansing the surface of a face panel 1, a carbon tripe 2 is formed by using a lithographic technique. Next, each of primary color fluorescent stripes 4G, 4B, 4R is formed by the method of applying fluorescent slurry containing a photosensitive agent thereto, hardening the corresponding part of a hole part 11 by light exposure and developing to remove unexposed parts. For the photosensitive agent, at least two kinds of compounds of diazo series, diazizo series and stilbazol series are used in combination. Resin stripes 12, 13, 14 are provided according to the application of an index tube and besides an intermediate film 15, a metal protective layer 5 and an index stripe 6 are formed in the upper part thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fluorescent screen for CRT, and more particularly to a method for producing a fluorescent screen for CRT on an inner surface of a face plate of an index tube used for aircrafts, vehicles and the like.

[0002]

2. Description of the Related Art In recent years, as a light emitting color display device, a so-called black stripe type device has been developed in which a face plate surface is treated with a non-emissive light absorbing substance such as carbon black in order to enhance contrast. As such a black stripe type color display device, an index tube used for a radar display device for an aircraft, a display device for a vehicle, etc. is known in addition to a cathode ray tube for a TV monitor. The index tube does not have an aperture grill, color selection is performed by an index stripe (IS), and color display is realized by a single electron beam. Therefore, it has advantages such as high brightness, strong resistance to vibration, and little influence of geomagnetism.

Conventionally, as shown in FIG. 3, a fluorescent surface of an index tube has a carbon stripe (CS) 2 formed on an inner surface of a face plate 1, and a carbon stripe protective film 3 made of alumina sol is formed so as to cover the carbon stripe (CS) 2. The phosphor stripes (PS) 4 of three colors of red, green and blue are arranged at a predetermined position above the phosphor stripes. On the entire top surface of PS4,
A metal protective layer (MB) 5 made of aluminum is formed, and an index stripe (IS) 6 is arranged at a predetermined position above the metal protective layer (MB) 5. As described above, the major difference between the fluorescent screen of the index tube and the fluorescent screen of another light emitting type color display device is that an index stripe 6 is further provided on the metal protective layer 5.

As described above, in the conventional index tube, the carbon stripe 2 is covered with the carbon stripe protective film 3 made of alumina sol. This is the upper part of the metal protective layer 5 in the index tube. This is due to the fact that the index stripes 6 are formed at.

That is, when the step of forming the carbon stripe protective film 3 is omitted in the production of the index tube, if the baking is carried out as the final step after the formation of the index stripe 6, the carbon stripe may be partially removed. There was a problem that the phenomenon of graying occurred. Such a phenomenon rarely occurs unless the index stripe 6 is provided on the metal protective layer 5.

After forming the carbon stripe 2, the carbon stripe protective film 3 is coated on the carbon stripe 2 with alumina sol having a concentration of about 50 to 60% by weight, dried, and adhered to unnecessary portions such as a panel edge and an outer surface. It is formed by wiping off the alumina sol and then firing. However, such a decrease in yield due to defects such as splash and dust associated with the application of alumina sol, complexity of manual wiping operation of alumina sol adhering to unnecessary portions, and further such a carbon stripe protective film forming step are required. As a result, many problems such as prolongation of manufacturing time and improvement of equipment / manufacturing cost have occurred, and establishment of a method of manufacturing an index tube that does not require the formation of such a carbon stripe protective film is desired.

The phosphor stripes 4 and the index stripes 6 are formed by the photolithography technique. That is, a photosensitizer is added to a slurry prepared by suspending a predetermined phosphor in an aqueous medium, and after coating and drying the slurry, a specific portion of the formed film is cured by exposure using a mask, It is formed by removing the exposed portion by development. As a photosensitizer added to such a phosphor slurry, a chromium-based photosensitizer such as ammonium dichromate has been conventionally used.

[0008]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The inventors of the present invention have partially disappeared or grayed out carbon stripes that occur when the step of forming a carbon stripe protective film made of alumina sol is omitted in the production of such an index tube. As a result of intensive studies to prevent the phenomenon, the phenomenon of corrosion of the carbon stripe is due to the influence of the chromium-based photosensitizer added to the phosphor slurry used in the step of forming the phosphor stripe. In the phosphor slurry for the index stripe used in the step of forming the index stripe, or the photosensitizer added to the phosphor slurry of each of the additive three primary colors used in the step of forming the phosphor stripe. At least one of the photosensitizers added to The With chromium-based photosensitive agent,
The inventors have found that the above-described corrosion phenomenon on the carbon stripe is almost eliminated, and have reached the present invention.

The present invention allows the formation of desired stripes of non-emissive light absorbing material on the face panel surface.
A first object is to provide a method for producing an RT phosphor screen. The present invention also does not require the formation of an alumina sol film as a protective film for the non-emissive light absorbing material stripe,
It is a second object of the present invention to provide a method for manufacturing an index tube which is free from the risk of deterioration of the formed stripes of the non-light emitting and light absorbing material.

[0010]

In order to solve the above first object, the present invention provides a phosphor slurry containing a photosensitizer after forming a stripe of a non-emissive light absorbing substance on the surface of a face panel. In a method for producing a phosphor screen for CRT, in which a specific portion of the phosphor slurry coating film is cured by exposure, and a non-exposed portion is removed by development to form a phosphor stripe. As the photosensitizer, at least two kinds of water-soluble diazo compounds, water-soluble diazo compounds and water-soluble stilbazole compounds are used in combination.

In order to solve the above-mentioned second object, the index tube manufacturing method of the present invention comprises forming stripes of a non-emissive light-absorbing substance on the surface of the face panel, and then adding each of the three primary colors to the respective primary colors. The phosphor-containing slurry containing the phosphor is used to form phosphor stripes of three colors of red, green and blue, and then a stripe of the non-emissive light-absorbing substance and the phosphor stripes of three colors of red, green and blue are formed on the face panel surface. Form a metal protective layer from the top, further on the metal protective layer, the slurry of the phosphor for the index stripe is applied, and a specific portion of the film formed by the phosphor slurry for the index stripe is cured by exposure, A method for manufacturing an index tube in which an unexposed portion is removed by development to form an index stripe. At least one of the color phosphor slurry and the index stripe phosphor slurry contains a photosensitizer formed by combining at least two kinds of water-soluble diazo compounds, water-soluble diazo compounds and water-soluble stilbazole compounds. It is characterized by

[0012]

In the method for producing a phosphor screen for CRT of the present invention, at least two kinds of water-soluble diazo compounds, water-soluble diazo compounds and water-soluble stilbazole compounds are used as the photosensitizer contained in the phosphor slurry. Since they are made non-chromatized in combination, the temperature of chromic acid rises when baking is performed in the final step of forming the fluorescent film, and stripes of a non-emissive light-absorbing material such as carbon stripes. There is no phenomenon such as burning and part of it disappearing or turning gray. As a result, it becomes unnecessary to form a protective film for protecting the carbon stripe.

In the method for manufacturing an index tube of the present invention, a water-soluble diazo compound or a water-soluble diazo compound is used as a photosensitizer contained in each primary color phosphor slurry and / or index stripe phosphor slurry. And a photosensitizer formed by combining at least two of water-soluble stilbazole compounds. As described above, by dechromizing the photosensitizer contained in the phosphor slurry, there is a phenomenon that a part of the stripe of the non-emissive light absorbing substance such as carbon black disappears or becomes gray. It can be prevented. In particular, it is advantageous in terms of cost to change the photosensitizer added to the index stripe phosphor slurry to a non-chrome type.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to a manufacturing process of an index tube used for an aircraft radar display device.

FIG. 1 is a flow chart showing the manufacturing process of the index tube, and FIG. 2 is a sectional view schematically showing the state in each manufacturing process of the face panel of the index tube. As shown in FIG. 1, in manufacturing the index tube, first, a stripe of carbon black as a non-emissive light absorbing substance is formed. The formation of the stripes in the carbon stripe is performed by first cleaning the surface of the index tube face panel, and then forming the photosensitizer and polyvinyl alcohol (P
A photoresist composed of a water-soluble polymer such as VA) is applied and dried to form a resist coating, and a predetermined portion of the resist coating is exposed and cured using a mask. Next, the non-exposed portion of the resist film is removed by development, and dots of the resist film are formed by drying, then a carbon black suspension is applied to the entire face panel, dried, and then a reversal solution is applied and developed. Dry to form carbon black stripes. FIG. 2A shows a state in which the carbon stripes 2 are formed on the face panel 1 in this way.

Next, as shown in FIG. 2B, the resin stripes 1 are formed in the hole portions 11 between the carbon stripes 2.
2 is formed by the same photolithography technique using a photoresist composed of a photosensitizer and a water-soluble polymer, as described above. The water-soluble polymer stripe 12 need not be provided depending on the use of the index tube. Next, phosphor stripes of three colors of red, green and blue are formed in the hole portions between the carbon stripes. First, a green phosphor slurry consisting of a green phosphor, a photosensitizer and a water-soluble polymer is applied to the entire face panel and dried to form a green phosphor resist coating, and a predetermined portion of the resist coating is exposed using a mask. Then, the green phosphor resist coating is developed to remove the unexposed portion, and dried to form a green phosphor stripe. As the green phosphor, for example, the host crystal is zinc sulfide, silver,
A material containing copper, aluminum or the like as an additive is used. FIG. 2C shows that the green phosphor stripe 4G is formed in a specific portion of the hole portion 11 between the carbon stripes 2.
Shows the state in which the is formed. After that, for example, the blue phosphor stripes 4B and the red phosphor stripes 4R containing the blue phosphors made of the same material as the green phosphors are replaced with the green phosphor stripes in the same manner as the formation of the green phosphor stripes 4G. The holes are formed in different hole portions adjacent to the hole portion 11 in which 4G is formed. As the red phosphor, for example, one containing yttrium oxysulfide as a host crystal and Euroview as an additive is used.

When the phosphor stripes of the three colors of red, green and blue are formed in this way, as shown in FIG. 2D, the resin stripes 13 are formed on the phosphor stripes 4 of the three colors of red, green and blue.
Is formed by the same method as described above for the purpose of improving brightness. Like the resin stripe 12, the resin stripe 13 need not be provided depending on the use of the index tube. Next, an intermediate film 15 is formed on the entire upper surface of these laminates, aluminum is vacuum-deposited thereon as a metal protective layer 5, and the surface of the metal protective layer 5 is treated with permanganate to prevent fogging. To do. FIG. 2E shows a state in which the intermediate film 15 and the metal protective layer 5 are formed. After the metal protective layer is formed in this manner, as shown in FIG. 2F, the resin stripe 14 is formed on the metal protective layer 5 at a specific portion located above the portion where the carbon stripe 2 exists.
It is formed by the same method as described above. Like the resin stripe 12, the resin stripe 14 need not be provided depending on the use of the index tube.

Next, an index stripe is formed on the metal protective layer at a specific portion located above the portion where the carbon stripe 2 exists. The formation of the index stripe is performed by the phosphor for the index stripe,
Apply a phosphor slurry for index stripes consisting of photosensitizer and water-soluble polymer to the entire face panel,
Form a phosphor resist coating for index stripes by drying, cure a predetermined portion of the resist coating by exposure using a mask, remove the non-exposed portion of the phosphor resist coating for index stripes by development,
Dry to form index stripes. In the present invention, as the photosensitizer blended in the phosphor slurry for index stripes, a combination of at least two kinds of water-soluble diazo compounds, water-soluble diazo compounds and water-soluble stilbazole compounds is used. Be done. The formation pattern of the index stripes is not particularly limited, but for each phosphor stripe 4,
Alternatively, it is formed for every four phosphor stripes 4.

Examples of the water-soluble diazo compound used in the present invention include benzidine tetrazonium chloride, 3,3'-dimethylbenzidine tetrazonium chloride, and 3,3'-dimethoxybenzidine tetrazonium chloride. Examples include tetrazonium chloride of 4,4'-diaminodiphenylamine, tetrazonium sulfate of 3,3'-diethylbenzidine, formalin condensate of diazophenylamine, and double salts thereof.

As the water-soluble diazo compound, 4,
4'-diazidostilbene-2,2'-disulphonic acid, 4,4'-diazidobenzalacetophenone-2-
Examples include sulfonic acid, 4,4'-diazidostilbene-2-carboxylic acid and salts thereof. Examples of water-soluble stilbazole compounds include stilbazolium salts.

The combination of these water-soluble diazo compounds, water-soluble diazo compounds and water-soluble stilbazole compounds is not particularly limited. As the water-soluble polymer compounded in this phosphor slurry, for example, P
VA, polyvinylpyrrolidone (PVP), polyacrylamide, polyvinyl methyl ether, polyvinyl acetal, polyacrylic acid, methyl vinyl ether-maleic acid copolymer, allyl amide-vinyl alcohol copolymer, acrylonitrile grafted polyvinyl alcohol, glycidyl methacrylate polyvinyl alcohol , Β-oxyethyl methacrylate grafted polyvinyl alcohol, carboxymethyl cellulose, hydroxymethyl cellulose, poly-L-glutamic acid sodium salt, gelatin, gum arabic, casein and the like, and these may be used alone or in combination,
Of these, PVA, PVP and combinations thereof are preferable.

A phosphor slurry prepared using a chromium-based photosensitizer such as ammonium dichromate and PVA or PVP, which has been conventionally used, is excellent in sensitivity, adhesiveness, developability, etc. As the photosensitizer, a combination of at least two kinds of water-soluble diazo compounds, water-soluble diazo compounds and water-soluble stilbazole compounds is used, and PVA or P is used as the water-soluble polymer.
The photoreceptor slurry prepared by using VP or the like has almost the same adhesiveness and developability as the conventional phosphor slurry, and the sensitivity is about 60 to 70%, which is practically no problem.

As described above, in this embodiment, at least two kinds of water-soluble diazo compounds, water-soluble diazo compounds and water-soluble stilbazole compounds were used as the photosensitizer in the index stripe phosphor slurry. In order to achieve non-chromatization by using a combination of the above, in the drying process of this phosphor slurry for index stripes, the heat fogging phenomenon peculiar to chromium-based photosensitizers is hardly seen, and the drying temperature can be raised. Therefore, the drying time can be shortened. In addition, since no chromium-based sensitizer is used as described above, it is expected that the brightness of the formed index stripe can be improved.

After forming the index stripes 6 as shown in FIG. 2 (g), baking is finally performed to fix the fluorescent coating on the face panel. As described above, in the present embodiment, since no chromium-based photosensitizer is used in the index stripe phosphor slurry, it partially disappears due to corrosion of the metal protective layer and burning of the carbon stripe when baking is performed. There is no phenomenon such as graying out, and high-quality index tubes can be manufactured.

In the above examples, the present invention has been described by taking the production of index tubes as an example. However, the present invention shows that the photosensitizer contained in the phosphor slurry is a water-soluble diazo compound as described above, By combining at least two kinds of water-soluble diazo compounds and water-soluble stilbazole compounds, it can be applied to the pattern formation of the fluorescent coating of other light emitting color display devices,
This makes it possible to provide an extremely high-quality light emitting color display device without deteriorating the stripes of the non-light emitting light absorbing material formed on the surface of the face panel.

The present invention will be described in detail below with reference to various experimental examples. Reference Example After forming a carbon stripe, an index tube was manufactured without forming a protective film of alumina sol, and ammonium dichromate (ADC) was used as a photosensitizer blended in the index stripe phosphor slurry.
The amount added was varied from 0.1 to 4.0% by weight, and it was observed how the burned state of the carbon stripes changed with changes in the amount added. The results are shown in Fig. 4. The amount of the other components in the index stripe phosphor slurry was 420 g of phosphor, 450 cc of PVA, and 47 of pure water.
It was 0 cc. As is clear from the results shown in FIG.
It was confirmed that the burned state of the carbon stripe became worse as the amount of ammonium dichromate added increased.

Example 1 After forming the carbon stripes, an index tube was manufactured without forming a protective film of alumina sol, and a PVA-stilvasolium-based resist (commercial product) was used as a photosensitizer to be blended in the phosphor slurry for index stripes. Name KIP) and p-diazodiphenylamine formalin condensate (DAZ), and the addition amount of DAZ is 0.5.
It was varied from ˜4.0% by weight, and it was observed how the burned state of the carbon stripe changed with the change of the addition amount. Results are shown in FIG. The amount of the other components in the index stripe phosphor slurry is the same as that of the phosphor 26.
It was 0 g, KIP 360 cc, and pure water 577 cc. As is clear from the results shown in FIG. 5, no burning of the carbon stripe was observed in any of the compositions.

Example 2 An index tube was manufactured without forming a protective film of alumina sol after forming a carbon stripe. The compositions of the green phosphor slurry, the blue phosphor slurry, the red phosphor slurry, and the index stripe phosphor slurry used were as shown in Table 1. Table 4 shows the result of observing the burning situation of the carbon stripes in the obtained index tube.

[Table 1]

Example 3 An index tube was manufactured without forming a protective film of alumina sol after forming a carbon stripe. The compositions of the green phosphor slurry, blue phosphor slurry, red phosphor slurry, and index stripe phosphor slurry used were as shown in Table 2. Table 4 shows the result of observing the burning situation of the carbon stripes in the obtained index tube.

[Table 2]

Comparative Example An index tube was manufactured without forming a protective film of alumina sol after forming a carbon stripe. The compositions of the green phosphor slurry, the blue phosphor slurry, the red phosphor slurry, and the index stripe phosphor slurry used were as shown in Table 3. Table 4 shows the result of observing the burning situation of the carbon stripes in the obtained index tube.

[Table 3]

[Table 4] As is clear from the results shown in Table 4, Examples 2 and 3
No burning of carbon stripes was observed in the index tube. In particular, the fact that the second embodiment exhibits the same effect as that of the third embodiment shows that it is extremely advantageous to form the index tube with the structure as in the second embodiment from the viewpoint of cost.

[0031]

As described above, according to the present invention, by making the phosphor slurry non-chromium, a non-luminous property is obtained in the pattern formation of the phosphor coating of the face panel of the light emitting color display device such as the index tube. Stripes of light-absorbing material are no longer damaged by the photosensitizer used in forming the phosphor stripes,
It is possible to provide a high-quality light emitting color display device. Further, since the stripe of the non-emissive light-absorbing material is not damaged, it is not necessary to form a special protective film for protecting the stripe, defects due to the protective film formation are eliminated, and the process is shortened. Can be planned. In particular, it is possible to improve the brightness of the index stripe by making the slurry of the phosphor for the index stripe non-chrome.

[Brief description of drawings]

FIG. 1 is a flowchart showing a manufacturing process of an index tube according to the present invention.

2 (a) to 2 (g) are cross-sectional views schematically showing a state in each manufacturing process of a face panel of an index tube.

FIG. 3 is a cross-sectional view schematically showing the structure of a conventional fluorescent coating of an index tube.

FIG. 4 is a graph showing the relationship between the burned state of carbon stripes and the amount of ammonium dichromate added.

FIG. 5 is a graph showing the relationship between the burned state of carbon stripes and the amount of diazo-based photosensitizer added.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Face panel, 2 ... Carbon stripe, 3 ... Carbon stripe protective film, 4 ... Red-green-blue three-color phosphor stripe, 4G ... Green phosphor stripe, 4B ... Blue phosphor stripe, 4R ... Red phosphor stripe, 5 ... Metal protective layer, 6 ... Index stripe, 11 ... Hole portion.

Claims (3)

[Claims] 1. A method for producing a phosphor screen for a CRT, comprising forming a stripe of a non-emissive light absorbing substance on a surface of a face panel, and then forming a phosphor having a predetermined pattern using a phosphor containing a photosensitizer. As a photosensitizer contained in the phosphor slurry, at least two kinds of a water-soluble diazo compound, a water-soluble diazo compound and a water-soluble stilbazole compound are used in combination, How to make. 2. The method for producing a phosphor screen for a CRT according to claim 1, wherein the stripe of the non-emissive light absorbing material is a carbon stripe. 3. After forming a stripe of a non-emissive light-absorbing substance on the surface of the face panel, for each of the additive three primary colors, a phosphor stripe of three colors of red, green and blue is prepared by using a slurry containing a photosensitizer of the phosphor of each primary color. Then, a metal protective layer is formed on the face panel surface from the stripes of the non-emissive light-absorbing material and the phosphor stripes of the three colors of red, green and blue, and an index is further formed on the metal protective layer. An index tube for forming an index stripe by applying a slurry of a stripe phosphor, curing a specific portion of the coating film formed by this index stripe phosphor slurry by exposure, and removing the unexposed portion by development A manufacturing method, wherein the phosphor slurry of each of the primary colors and the slurry of the index stripe phosphor Without even one is a water-soluble diazo compounds, a manufacturing method of the index tube, characterized by containing a photosensitive agent comprising a combination of at least two of the water-soluble Jiajizo compound and water-soluble stilbazole compounds.