JPH06302270A - Fluorescent screen forming method - Google Patents

Abstract

PURPOSE:To improve the productivity by transferring a necessary part of all the stripes to a glass substrate in a stripe form at first, and then, moving a thermal transfer type phosphor layer component remaining on a transfer member to the stripe position to transfer next, and carrying out the transfer. CONSTITUTION:A transfer member 7 is superposed on a face plate 8, and a thermal head 9 having a heater of a dot/mm is applied and run while pressing it. In this case, in one line the thermal head 9 is being applied, the transfer member 7 is not moved perfectly, and after applying the thermal head 9, the transfer member 7 is removed at once. In two lines where the thermal head 9 is not applied, the transfer member 7 is moved in the moving direction of the head 9 at the distance same as the distance subtracting the stripe width from the moving distance of the head 9. As a result, a fine stripe form of phosphor layer 10 can be formed on the plate 8. On the transfer member 7 used for transferring, the phosphor layer 10 is transferred continuously. Consequently, the thermal transfer type phosphor layer 10 on the transfer member 7 is used to copying usefully and effectively, and the cost can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for easily and efficiently forming a fluorescent film on a glass substrate, particularly on a face plate of a cathode ray tube.

[0002]

2. Description of the Related Art Conventionally, a slurry coating exposure method or a sedimentation method has been used as a method for forming a fluorescent film on a face plate of a cathode ray tube. In the slurry coating exposure method for forming the fluorescent film described above, a slurry in which a phosphor is dispersed in a photosensitive resin composed of polyvinyl alcohol and ammonium dichromate is spin-coated on a face plate.
Dry and expose the desired pattern with UV light. After that, it is developed with water to remove the unexposed portion and form a fluorescent film.

The method of forming a fluorescent film by the sedimentation method is
In this method, a phosphor is allowed to settle on a face plate in a suspension containing the phosphor and a binder (water glass or the like), and then the supernatant is gently poured to form a phosphor film.

[0004]

When the fluorescent film is formed by the slurry coating exposure method, there are disadvantages that the number of steps is large, the apparatus is complicated, and the productivity is low. The sedimentation method has drawbacks that it takes time to sediment the phosphor and it is difficult to form a predetermined pattern.

An object of the present invention is to solve the above problems and to provide a method for forming a fluorescent film which enables easy and efficient formation of a fluorescent film on a glass substrate, especially on a face plate of a cathode ray tube. That is.

[0006]

Means for Solving the Problems As a result of intensive studies made by the present inventors, a transfer material is used if a thermal transfer method is used and a part of the transfer material that is not transferred is moved to a position to be transferred next time. The present invention has been accomplished by finding out that it can be effectively used without being wasted. That is, the gist of the present invention is a transfer material in which a heat transferable phosphor layer containing at least a phosphor and a heat-meltable binder is formed on a base film, the heat transferable phosphor layer is opposed to a glass substrate, and the heat transfer is performed. In a stripe type fluorescent film forming method of forming a fluorescent film on the glass substrate by transferring the fluorescent phosphor layer onto the glass substrate in a predetermined stripe shape by a thermal transfer method and baking the fluorescent film. The transfer of the glass substrate is first performed by transferring a part of all the stripes necessary for the glass substrate in a stripe shape, and then the thermal transferable phosphor layer portion remaining on the transfer material is next transferred to the stripe position. The present invention resides in a method for forming a fluorescent film, which is characterized in that it is carried out by moving to

The present invention will be described in detail below, taking as an example the case where a fluorescent film is formed on the face plate of a cathode ray tube. The thermal transfer recording method is an ink ribbon having a heat-meltable ink on a substrate, as widely used in personal word processors and color printers at present.
In this method, a desired pattern is formed by heat-pressing only a desired portion from the back side of the ink layer with a heating source such as a thermal head.

The transfer material used in the present invention has a heat transferable phosphor layer containing at least a phosphor and a heat-meltable binder on the base film. As the base film, a conventionally well-known film, paper or the like can be used. Examples thereof include resin films having relatively high heat resistance such as polyester, polypropylene, polyamide, polycarbonate, polyimide, cellophane, and paper such as glassine paper and condenser paper. The thickness is preferably 1 to 20 μm. This base film may be provided with a heat resistant slipping layer such as a silicone resin on the side in contact with the thermal head in order to improve heat resistance and running performance of the thermal head.

Examples of phosphors used in the present invention include:
Silver-activated zinc sulfide-based phosphor as a blue-emitting component phosphor, eg
For example, at least 1 of ZnS: Ag, ZnS: Ag, and Al.
Species, as a green light emitting component phosphor, copper activated zinc sulfide based fluorescent
Body, eg ZnS: Cu, Al phosphor and ZnS: Au,
Mixed phosphor of Al phosphor, ZnS: Cu, Al phosphor,
Gold, copper, and aluminum activated zinc sulfide phosphor (Zn
S: Au, Cu, Al), copper and aluminum activated sulfur
Zinc bromide / cadmium phosphor [(Zn, Cd) S: Cu,
At least one of Al], and a red light emitting component phosphor
-Ropium-activated rare earth oxide phosphors such as europium
Um-activated yttrium oxysulfide phosphor (Y ₂O₂S: E
u), europium-activated yttrium oxide phosphor (Y₂
O₃S: Eu) at least one type of conventional cathode ray
The phosphors used in the tubes can be used.
In addition, pigments with filter hardening are attached to these phosphors.
The one worn is also used. Examples of this type of pigment include
For blue light emitting phosphors, a blue color such as cobalt aluminate or ultramarine blue
TiO for pigment and green light emitting phosphor₂・ ZnO ・ CoO ・
NiO-based green pigments, red light emitting phosphors
There are red pigments such as cadmium sulfate selenide. Large phosphor
As the size, a range of 1 to 20 μm is desirable, and a range of 2 to 8
The range of μm is more desirable.

As the hot-melt binder, waxes such as paraffin wax, microcrystalline wax and carnauba wax, various synthetic waxes, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyester resin, polyamide resin Thermoplastic resins such as and the like can be used. In addition, petroleum resins, rosin derivatives, various plasticizers, softening agents such as liquid paraffin, and various dispersants for dispersing the phosphor can be used, if necessary.

The ratio of the phosphor to the heat-meltable binder is 20 to 80% by weight of the phosphor and 80 to 2 of the heat-meltable binder.
0 wt% is desirable. As a method for providing the heat transferable phosphor layer on the base film, it can be provided by applying a hot melt binder in which the phosphor is dispersed by a method such as hot melt coating, solvent coating, or emulsion coating. .
The thickness of the heat transferable phosphor layer is preferably in the range of 3 to 60 μm, more preferably 5 to 30 μm. If this is too thin, the amount of the phosphor material in the phosphor film formed on the glass substrate tends to be insufficient, and if it is too thick, heat transfer to the heat transferable phosphor layer becomes insufficient, and the predetermined pattern This is because it tends to be difficult to form.

The transfer material may include a base material and a heat transferable phosphor layer in order to improve the adhesiveness of the heat transferable phosphor layer to the base material and, conversely, the releasability from the base material, if necessary. An adhesive layer and a peeling layer can be provided between the two. The thickness of the adhesive layer and the peeling layer is preferably in the range of 0.1 to 2 μm. Other,
In order to improve the adhesiveness to the face plate surface, it is possible to further provide an adhesive layer on the surface of the heat transferable phosphor layer. The thickness of this adhesive layer is 0.1 to 2 μm
The range of is desirable.

1 to 3 show an example of an embodiment of the transfer material used in the present invention. In each figure, (1) is a phosphor,
(2) represents a heat-meltable binder. FIG. 1 shows an example in which a heat transferable phosphor layer (4) is provided on a base film (3), and FIG. 2 shows (5) between a base material (3) and the heat transferable phosphor layer (4). 3 is an example in which an adhesive layer (6) is further provided in the configuration example of FIG. 1.

A fluorescent film is formed on the face plate of the cathode ray tube by using the above-mentioned thermal transferable transfer material. The transfer material is superposed on the face plate, the direction of arrangement of the heating elements of the line thermal head is placed in parallel with the stripes of the phosphors at the position where the stripes are to be formed, and application and scanning are performed while pressing with the thermal head. At this time, the transfer material does not move while the phosphor layer is being transferred to the thermal head, and when the transfer is complete, it is approximately the same as the moving distance of the thermal head minus the amount corresponding to the stripe width. , The transfer material is moved in the moving direction of the thermal head to perform the next transfer.

More specifically, a) In the case where the thermal head transfers only one stripe in a series of operations, first one stripe (usually the end) is transferred first, and then the thermal heads have adjacent stripes of the same color. The transfer material is moved to a position, while the transfer material is moved by a distance obtained by subtracting the width of one stripe (set as a) from the moving distance of this thermal head (set as A), that is, A-a. And then repeat this method. B) A thermal head has a plurality of two or more in a series of operations (this number is X)
When transferring stripes of a book, after transferring X stripes first, the thermal head is moved a distance A from the position of the stripe where the last transfer was made, and the transfer material is A · X−
When the next transfer is performed by moving the distance a, and the transfer is performed three times including the first transfer, the thermal head moves the distance A as in the above b) and the transfer material moves the distance A. Repeat the operation of. C) When a plurality of rows of thermal heads are installed and this number of stripes is transferred in a series of operations, the moving distance of the thermal head after transferring X stripes first is always AX as a whole. Except for the above, the same operation as above may be performed. In practice, it is advisable to adopt, as the above-mentioned a, a width obtained by adding a margin width of about 1/5 to the width of one stripe.

Further, in the case of the above (b), the stripe number X corresponding to 1/3 of all stripes is first transferred in a series of operations, and in the case of the above (c), the first X number of stripes are transferred. The transfer material is not moved but the thermal head is moved a distance of A / X for the next transfer, and this procedure is repeated until the number of transferred stripes reaches X, and then the transfer material is moved to A / X-a for the first time. Then, by repeating each of the above operations, the transfer material can be moved three times to transfer all the required stripes, and the width of the transfer material is about 1/3 of the width of the glass substrate to be transferred. In the case of the above (c), if the thermal heads are installed in X rows, it is possible to immediately move to the operation of moving the transfer material in a series of transfers. As will be easily understood by those skilled in the art, these operations have been described on the assumption that stripes of red, blue and green are normally and repeatedly set in a cathode ray tube of a television or various full color display tubes. If the number of these colors is different for some reason, the specific operation may be changed according to the number. It will also be clearly understood that in the present invention the total number of stripes means the total number of stripes of the same color, but not all of these plural colors. As described above, according to the present invention, in the transfer material, almost all the transfer layers are transferred,
The stripe type phosphor layer is effectively used. If the transfer material is peeled off immediately after application, the heat transferable phosphor layer is transferred in a stripe pattern. The surface of the phosphor layer has excellent smoothness.

Next, the face plate is fired together with the transferred phosphor layer, and the main purpose of this firing is to remove organic components other than the phosphor and the coloring pigment.
Therefore, as long as it does not adversely affect the phosphor and the adhered pigment, any suitable temperature may be adopted depending on the above purpose, but it is usually desirable to select from the range of 400 to 500 ° C.
Thus, the fluorescent film is formed.

[0018]

The present invention will be described in more detail with reference to the following examples, but the invention is not limited to the following examples as long as the gist thereof is not exceeded. In the examples, "part" is "part by weight".
Indicates.

[Embodiment] A polyethylene terephthalate film (6 μm) whose back surface on which ink is applied is heat-resistant and slip resistant.
m) and an ink having the following composition with a dry coating thickness of 15
coated by the microgravure method so that
A transfer material was obtained.

[0020]

Composition: Ethylene-vinyl acetate resin emulsion 10 parts (solid content 40%) Paraffin wax emulsion 20 parts (solid content 40%) Phosphor powder (ZnS: Cu, Al, average particle size 4.0 μm) 24 parts Water 30 copies As shown in FIG. 4, this transfer material (7) was superposed on the face plate (8), and was pressed by the prototype line head (9) having a heating element of 6 dots / mm, while applying and scanning under the following conditions. Let At this time, the transfer material was not moved at all during the application of one line, and immediately after the application, the transfer material was peeled off. Then, the transfer material was moved in the moving direction of the thermal head by a distance approximately equal to the distance obtained by subtracting the stripe width from the moving distance of the thermal head between the two lines which were not applied. Then, a beautiful striped phosphor layer (10)
Was obtained on the face plate. Looking at the transfer material used for transfer, the phosphor layer was continuously transferred, and the phosphor layer was effectively used.

[0021]

[Table 2] Recording line density 6 dots / mm Thermal head applied power 0.2 W / dot Thermal head applied pulse width 12 ms Application pattern 1 line applied Repeated 2 lines not applied
Remove organic components by baking for 30 minutes at
A stripe type fluorescent film was formed.

[Comparative Example] The transfer material obtained in Example 1 was superposed on a face plate and pressed with a prototype line head having a heating element of 6 dots / mm, while applying and scanning under exactly the same conditions as in Example 1. Let At this time, the transfer material did not move at all until the end of the stroke. When the transfer material was peeled off, a beautiful striped phosphor layer was obtained on the face plate. Looking at the transfer material used for the transfer, the phosphor layer was transferred in a jumping manner as shown in FIG. Cage,
Only 1/3 of the phosphor layer was used.

[0023]

According to the present invention, the thermal transfer phosphor layer is
Since it can be easily transferred onto the glass substrate by thermal transfer, the productivity of the fluorescent film forming step is greatly improved. At that time, the heat transferable phosphor layer on the transfer material is effectively used for transfer without waste, so that the cost of the transfer material can be very low.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a transfer material for forming a fluorescent film of the present invention.

FIG. 2 is a cross-sectional view showing an embodiment of a transfer material for forming a fluorescent film of the present invention.

FIG. 3 is a sectional view showing an embodiment of a transfer material for forming a fluorescent film of the present invention.

FIG. 4 is an explanatory diagram of a transfer system of the present invention.

FIG. 5 is an explanatory diagram of a transfer method of a comparative example.

[Explanation of symbols]

 1 Phosphor 2 Thermal Melting Binder 3 Base Film 4 Thermal Transfer Phosphor Layer 5 Adhesive Layer or Release Layer 6 Adhesive Layer 7 Transfer Material 8 Face Plate 9 Thermal Head 10 Transferred Phosphor Layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiko Kuroda 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd. (72) Inventor Yasushi Oguri 1000-1 Kamoshita-cho, Midori-ku, Yokohama, Kanagawa (72) Inventor Hiroshi Uchida 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa San Ryokasei Co., Ltd.

Claims (4)

[Claims] 1. A thermal transferable phosphor layer of a transfer material having a thermal transferable phosphor layer containing at least a phosphor and a heat-meltable binder formed on a base film, the thermal transferable phosphor layer being opposed to a glass substrate. A stripe type fluorescent film forming method of forming a fluorescent film on a glass substrate by transferring a body layer to a glass substrate in a predetermined stripe shape by a thermal transfer method, and firing the glass substrate of the thermal transferable phosphor layer. First, a part of the entire stripe required for the glass substrate is transferred into a stripe shape, and then the thermal transferable phosphor layer portion remaining on the transfer material is moved to the stripe position to be transferred next. Method for forming a fluorescent film 2. The method for forming a fluorescent film according to claim 1, wherein a part of all stripes required for the glass substrate is one stripe. 3. The method for forming a fluorescent film according to claim 1, wherein a part of all stripes required for the glass substrate is a plurality of stripes. 4. The method for forming a fluorescent film according to claim 3, wherein a part of all stripes required for the glass substrate corresponds to 1/3 of all stripes.