JPH0233825A - Fluorescent film formation method for cathode-ray tube - Google Patents

Abstract

PURPOSE:To efficiently form a fluorescent film by forming a transfer material having a fluorescent material layer of an area more than necessary in a widthwise direction, transferring the fluorescent material layer onto a face plate via a roll transfer method after slitting the aforesaid transfer material and then baking the layer. CONSTITUTION:A peel layer 2 is formed on a polyester film 1 through a gravure printing method, using an ink comprising a composition 1 and a fluorescent material layer 5 having a size, for example, of 38mm (height)X64m (width) is formed on the peel layer 2 through a screen printing method, using another ink comprising a composition 2. Thereafter, a conductive layer 4 of 64mm width is formed thereon through the screen printing method, using another ink comprising a composition 3 to a pattern narrower than the inner dimension of the connection corresponding to a funnel connection. Furthermore, an adhesive layer 6 is so formed as to totally cover the fluorescent material layer 5 and the conductive layer 4 through the screen printing method, using another ink comprising a composition 4, thereby obtaining a transfer material 7. This transfer material 7 is slit to a width of 54mm with a round tooth and the slit transfer material 7 is transferred to a face plate 8 with the roll transfer method. A heating roll of 35mm width comes to have a width of 54mm due to the thermal expansion thereof during a heating process, and a necessary fluorescent film is thereby formed on the face plate 8.

Description

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

The present invention relates to a method for efficiently forming a fluorescent film on the face plate of a cathode ray tube.

[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. In addition, a printing method has recently become available as a method for forming a phosphor film for a cathode ray tube, which has a simple process, low equipment cost, and significantly less loss of phosphor. In the printing method, a fluorescent film is formed as follows. First, an ink with an appropriate viscosity is prepared by dispersing the phosphor in an appropriate binder.Next, this ink is applied onto the face plate by a printing method such as screen printing or gravure offset printing, and then dried. to form a dry coating film. Next, the face plate is fired, and the binder in the dried coating film is thermally decomposed and removed, so that the dried coating film becomes a fluorescent film consisting essentially only of phosphor. However, the printing method is a technology that can only be applied when the substrate to be printed is flat, and the substrate to be printed, that is, the face plate, is a flat cathode ray tube in which there is no rise at the top and a funnel connection part is formed at the bottom, which is narrower than the top. It cannot be applied to three-dimensional curved surfaces such as. In order to solve the above-mentioned problems, in recent years, a method for forming a fluorescent film for a cathode ray tube has been proposed in which a fluorescent film is formed even on a three-dimensionally curved face plate by a transfer method.

[Problems to be Solved by the Invention] However, this method also has the following problems when forming a fluorescent film on a face plate that has no rise at the top and a funnel connection section at the bottom that is narrower than the top. There are problems. To transfer a fluorescent film to a face plate using a transfer material, the adhesive layer side of the transfer material is placed on the face plate, and a heated elastic body is pressed from above to heat and pressurize the transfer material. The adhesive layer is fused to the face plate, the elastic body is removed, and after cooling, the base film is peeled off. Therefore, if we adopt a roll transfer method in which a roll made of silicone rubber or the like is used as an elastic body and is rolled, heated and pressurized, the above face plate will have a funnel connection part narrower in width than the upper part. Therefore, the actual transfer area is limited by the width of the lower part and is narrow. Therefore, if an attempt is made to make the most of the width of the lower portion for transfer, the roll or transfer material will come into contact with the inner surface of the funnel connection portion of the face plate, causing wear and damage. Therefore, as a transfer method, it has been necessary to rely on an up-down transfer method with low productivity, in which the transfer process is performed by pressing an elastic body from directly above the face plate.

[Means to solve the problem]

This invention solves the above problems and enables efficient manufacturing by applying the roll transfer method.
It was configured as follows. That is, the method for forming a phosphor film of a cathode ray tube of the present invention uses a transfer material having at least a phosphor layer on a removable base film, and forms a funnel connection portion with no rise at the top and a narrower width at the bottom than the top. In the conventional method of transferring a phosphor layer onto the face plate of a cathode ray tube, a transfer material having a phosphor layer larger in the width direction than the required area is formed, and then this transfer material is spread over the width of the funnel connection part. After slitting into
The phosphor layer was transferred onto the face plate by a roll transfer method, and then the phosphor layer was fired. The invention will be described in more detail with reference to concave surfaces. FIG. 1 is a sectional view showing one embodiment of a transfer material used in the present invention. FIG. 2 is a sectional view showing another embodiment of the transfer material used in the present invention. FIG. 3 is a sectional view showing the transfer process. FIG. 4 is a perspective view of the face plate. FIG. 5 is a diagram showing a state in which the transfer material is positioned on the face plate. FIG. 6 is a perspective view of the cathode ray tube. 1 is a base film, 2 is a release layer, 4 is a conductor layer, 5 is a phosphor layer, 6 is an adhesive layer, 7 is a transfer material, and 8 is a face plate. As the base film 1, there is used a plastic film such as polyethylene terephthalate, polypropylene, polyethylene, nylon, or cellophane, or a composite film of these and paper, which is used as a base film for ordinary transfer materials. In order to impart releasability to the base film 1, it is preferable to apply a silicone coat or a wax coat to the base film 1, or to provide a release layer 2 thereon. The peeling N2 is formed using a thermoplastic resin, natural rubber, synthetic rubber, or the like, by a normal printing method such as a gravure printing method, a screen printing method, or a roll coating method. As the phosphor layer 5, ZnS:Ag or SnS:
Cu. ^1. YJzS: A phosphor conventionally used in cathode ray tubes, such as Eu, is used, and an ink made of thermoplastic resin or the like as a binder is used. As a method for forming the phosphor N5, 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 N5 is formed on the base film l or the release layer 2, which has excellent smoothness, the surface of the base film 1 has excellent smoothness. If the cathode ray tube is 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. Further, a conductor layer 4 is formed as necessary. Conductor layer 4
is formed as a back electrode or to increase the contrast of the image and obtain a dense and uniform screen. In addition, by forming a conductive film on the face plate,
It is also easy to conduct with the anode button through the contact dunk. As the conductor layer 4, it is preferable to use a conductive ink obtained by using a conductor such as carbon graphite or NiCu-Al/Ag-Au using a thermoplastic resin as a binder. The conductor N4 is formed in a shape that is narrower than the funnel connection portion of the face plate 8 by 11 points or more (see FIG. 5). As a method for forming the conductor layer 4, in consideration of the required film thickness and the particle size of the conductor, it is desirable to print by screen printing. Since the cathode ray tube is a flat rear viewing type, the conductor layer 4 is formed between the phosphor N5 and the adhesive N6 (see FIG. 1). 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. Its formation method is
Ordinary printing methods such as gravure printing, screen printing, and roll coating may be used. The transfer material 7 having such a layered structure is slotted to the width of the funnel connection portion of the face plate 8 (see FIG. 5). If a razor blade is used for slitting, not only will burrs occur on the cut surface of the transfer material 7, resulting in foil spillage and foil lifting, but the thin blade will cause bending, resulting in poor accuracy. Slitting is difficult and is not desirable for small cathode ray tubes where the slit width is the same as the screen size. Therefore, it is desirable to slit with a round blade that has good slitting accuracy and does not cause foil spillage or foil lifting. 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,
Rolling a cylindrical elastic rubber while applying pressure on the transfer material 7 while heating it with a heater or the like,
The adhesive layer 6 is fused to the face plate 8. The temperature at this time is 130~230'C1 the pressure is 3~150kg/
cffl is suitable. In this way, when performing transfer processing using the roll transfer method, the cylindrical elastic rubber becomes larger than the set dimension at the time of transfer due to thermal expansion due to heating and distortion due to pressure during transfer, so the face plate 8 It is necessary to set the size smaller than the size of the funnel connection part. Next, when the base film 1 is peeled off, only the base film 1 is peeled off from the transfer material 7, and the adhesive layer 6, phosphor layer 5, etc. are transferred onto the face plate 8 (see FIG. 3). 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 to remove all organic components such as the binder of the adhesive layer 6 and the phosphor layer 5.
Only the phosphor or, if a conductive layer is formed, only the phosphor and the conductor are used to complete the fluorescent film or the fluorescent film and the conductive film.

【Example】

The face plate is 2. Finch rear viewing type flat C
This is for RT (see Figure 4). On a polyester film with a thickness of 25 μm, a film thickness of 1 μm was printed using the gravure printing method using an ink consisting of the following composition 1.
A phosphor layer of 38 μm in length and 64 mm in width was then provided thereon with a thickness of 30 μm using an ink having composition 2 by screen printing. Next, a conductor layer having a thickness of 10 t1 m was formed thereon by a screen printing method using an ink having composition 3, with a width of 641 mm, and a pattern in which the part corresponding to the funnel connection part was narrower than the inner dimension of the funnel connection part. Furthermore, a film thickness of 5 μm was formed by screen printing using ink consisting of composition 4 so as to cover the entire surface of the phosphor layer and conductor layer.
A transfer material was obtained by providing an adhesive layer (see FIG. 1). Composition 1 (Parts by weight) Acrylic resin 10 Toluene
45 methyl ethyl ketone
45 x 2 (parts by weight) Acrylic resin 20 Phosphor powder (Yz
OzS:Eu) 20 isophorone
10cyclohexanone
50 8/3 (parts by weight)
Acrylic resin 20 Conductor powder (Ag) 25 Isophorone
10cyclohexanone
45 x 4 (parts by weight) Polyamide resin 30 Ethyl cellosolve 30 Cyclohexanone
40 The thus obtained transfer material has a width of 54
It was slit with a round blade to a length of mm. Next, apply the slinted transfer material to the face plate for 15 minutes.
0°C15kg/c+! The image was transferred using the roll transfer method. The heating roll for transfer has a funnel connection part of the face plate of 54nua, so taking into account the thermal expansion of the roll during heating and roll distortion during transfer, the width at room temperature is 53nua.
mm was used. This roll had a width of 54 mm due to thermal expansion and pressure during transfer, and was able to form a transfer layer with the required fluorescent film shape and area on the face plate. Finally, organic components on the face plate were removed by baking at 450°C for 30 minutes, and a fluorescent film and a conductive film were formed on the face plate. Next, the funnel in which the electron gun and deflection yoke are built into this face plate is joined to the front panel.
．． A Finch cathode ray tube was obtained (see Figure 6).

【Effect of the invention】

This invention involves forming a transfer material with a phosphor layer that is thicker in the width direction than the required area, then slinting this transfer material to the required width, and then applying a phosphor layer onto the face plate using a roll transfer method. Since the structure is such that the body layer is transferred and then the phosphor layer is fired, even if the face plate has no rise at the top and a funnel connection part that is narrower than the top at the bottom, it can be easily processed using the roll transfer method. The fluorescent film can be efficiently produced and has excellent mass productivity.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of a transfer material used in the present invention. FIG. 2 is a sectional view showing another embodiment of the transfer material used in the present invention. FIG. 3 is a sectional view showing the transfer process. FIG. 4 is a perspective view of the face plate. FIG. 5 is a diagram showing a state in which the transfer material is positioned on the face plate. FIG. 6 is a perspective view of the cathode ray tube. DESCRIPTION OF SYMBOLS 1... Base film, 2... Peeling layer, 4... Conductor layer, 5... Phosphor layer, 6... Adhesive layer, 7...
Transfer material, 8... face plate. Patent applicant: Nissha Printing Co., Ltd.

Claims (1)

[Claims] 1. A funnel connection in which there is no rise in the upper part and the lower part is narrower than the upper part, using a transfer material (7) having at least a phosphor layer (5) on a removable base film (1). The face plate of the cathode ray tube (8
), a transfer material having a phosphor layer (5) larger in the width direction than the required area is formed, and then this transfer material (7) is transferred to a funnel connection part. Formation of a phosphor film for a cathode ray tube, characterized in that the phosphor layer (5) is transferred onto the face plate (8) by a roll transfer method, and then the phosphor layer (5) is fired. Method. 2. The transfer material (7) is a base film (
1) On top of that, phosphor layer (5), conductor layer (4), adhesive layer (
6. The method of forming a phosphor film of a cathode ray tube according to claim 1, wherein the phosphor layers 6) are sequentially laminated. 3. The method for forming a fluorescent film for a cathode ray tube according to claim 2, wherein the conductor layer (4) is formed so as to be transferred 1 mm or more inward from the end of the funnel connection part of the face plate (8). .