JPH0945241A - Flourescent screen forming thermal transfer sheet, and fluorescent screen forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fluorescent screen forming method, capable of easily and accurately forming a fluorescent screen pattern onto a glass substrate, in particular, on a glass substrate for a cathode-ray tube. SOLUTION: This sheet is composed by forming a phosphor layer; containing at least a phosphor pigment, thermal fusing binder resin, and a solvent; on a sheetlike base material having a linear expansion coefficient of 1×10<-4> or less, a thermal conductivity of 10 W.m<-1> .K<-1> or more, and a heat capacity of 2-5J.K<-1> , via a separation layer as necessary.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a glass substrate,
In particular, the present invention relates to a fluorescent film forming thermal transfer sheet and a fluorescent film forming method for easily and efficiently forming a fluorescent film on a face plate of a cathode ray tube.

[0002]

2. Description of the Related Art Conventionally, as a method for forming a fluorescent film on a face plate of a cathode ray tube, a slurry coating exposure method, a sedimentation method, etc. have been used, but the number of steps is large, the apparatus is complicated and the productivity is high. It had the drawback of being chipped. Therefore,
As a forming method with good productivity, an alternative method using a printing method such as screen printing, for example, Japanese Patent Publication No.
The method described in JP-A-46674 or JP-A-6-49398 has been proposed.

[0003]

The production of a fluorescent film by a direct screen printing method on a glass panel has high productivity and is extremely advantageous in terms of production equipment. However, the glass panel on which the fluorescent film is formed is a flat plate. Instead, it is a curved surface with a certain curvature. Therefore, it was difficult to screen print the black matrix and the phosphor matrix directly on the glass substrate. The present invention provides a phosphor film forming method capable of forming a phosphor film having higher productivity by taking advantage of the phosphor film forming method using a transfer sheet having good adhesion even to a curved surface as described above. With the goal.

[0004]

The present inventors have achieved the present invention as a result of intensive studies for achieving the above object.
That is, the first gist of the present invention is that the linear expansion coefficient is 1 × 10.
^-4 or less, a thermal conductivity of 10 W · m ⁻¹ · K ⁻¹ or more, and a heat capacity of 2 to 5 J · K ⁻¹ on a sheet-like base material, optionally via a release layer, and at least fluorescence. A thermal transfer sheet for forming a phosphor film, comprising a phosphor layer containing a body pigment, a heat-fusible binder resin, and a solvent.

The second gist of the present invention is that the coefficient of linear expansion is 5 × 10 ^-5 or less and the coefficient of thermal conductivity is 10 W · m ⁻¹ · K ⁻¹ or more,
And on a sheet-shaped substrate having a heat capacity of 2 to 5 J · K ⁻¹ ,
At least a phosphor pigment through a release layer, if necessary,
A thermal transfer sheet for forming a fluorescent film formed by forming a phosphor layer containing a heat-meltable binder resin and a solvent is brought into contact with a glass substrate, and a thermal transfer head is pressed from the back surface of the transfer sheet toward the glass substrate. A fluorescent film forming method is characterized in that the fluorescent film is thermally melt-transferred onto the glass substrate by relatively moving the thermal transfer head and the glass substrate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below, taking as an example the case where a fluorescent film is formed on a glass face plate of a cathode ray tube. As the sheet-shaped base material (hereinafter, simply referred to as a base material) used in the present invention, a material having a small thermal deformation, a good thermal conductivity and an appropriate heat capacity is used.
Therefore, the linear expansion coefficient of the base material is appropriately 1 × 10 ⁻⁴ or less, preferably 5 × 10 ⁻⁵ or less. Although the thermal conductivity changes slightly depending on the temperature, 10 W · m ⁻¹ · K ⁻¹ or more is suitable, 100 W · m ⁻¹ · K ⁻¹ or more is preferable, and 200 W
-M ^-1 · K ^-1 or more is more preferable. Heat capacity is 2-5J
・ It should be about K ^-1 . Examples of such a base material include metal foils such as aluminum, copper, and stainless steel. The thickness is preferably 2 to 1000 μm, more preferably 10 to 500 μm. If the thickness is less than 2 μm, the strength of the foil itself is weak and handling is difficult.
When the thickness is thicker, heat diffuses in the substrate in the planar direction, and the width of the stripe is widened during the thermal fusion transfer.

As the fluorescent film forming ink used in the present invention, an ink containing a binder resin, a solvent and a fluorescent pigment as main components is used. As the binder resin, a thermoplastic resin is preferable, and specifically, polyvinyl butyral resin, polyvinyl formal resin, polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, acrylic resin, polyester resin, cellulose resin or the like is used. Particularly, polyvinyl butyral resin and ethylene-vinyl acetate copolymer resin are preferable.

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 binder resin to the phosphor pigment is preferably 1 to 50 parts by weight, more preferably 2 to 20 parts by weight, based on 100 parts by weight of the phosphor pigment. If the amount of the binder resin is less than 1 part by weight, the binding force between the phosphors becomes weak, and the phosphors are likely to come off in the subsequent operation. On the other hand, if the amount is more than 50 parts by weight, the content of the phosphor becomes small and the emission intensity of the cathode ray tube becomes small.

The solvent used in the present invention is preferably a glycol ether type solvent, a glycol ester type solvent or a terpene type solvent, for example, methyl cellosolve,
Examples thereof include ethyl cellosolve, butyl cellosolve, methyl carbitol, ethyl carbitol, butyl carbitol, methyl cellosolve acetate, ethyl cellosolve acetate, carbitol acetate, and alpha or beta terpineol.

The amount of the above solvent used is preferably 5 to 200 parts by weight, more preferably 20 to 100 parts by weight, based on 100 parts by weight of the total of the phosphor pigment and the binder resin. When the amount of the solvent is less than 5 parts by weight, the clogging of the screen increases and the transfer omission increases, and when the amount of the solvent exceeds 200 parts by weight, the ink easily flows and the line thickening easily occurs during printing.

As an example of the phosphor used in the present invention
Is a P4 phosphor, for example, as a white phosphor for a white tube.
For example, Kasei Optonix P4-A (ZnS: Ag + Z)
nS: Au, Al + Y₂O₂S: Eu) P4-K "Zn
S: Ag + (Zn, Cd) S: Cu, Al ", color tube
Activated Zinc Sulfide-based Fluorescence as a Blue-Emitting Component Phosphor for LED
Body, for example, P22-B1 (ZnS: manufactured by Kasei Optonix)
Ag), P22-B2 (ZnS: Ag, Al), green emission
Copper-activated zinc sulfide phosphor as a light component phosphor, such as chemical conversion
Optonics P22-GN (ZnS: Cu, Al)
Mixed fluorescence with (ZnS: Au, Al) for P22-GN
Body, P22-GN (ZnS: Cu, Al), gold, copper,
And aluminum activated zinc sulfide phosphor P22-GY (Z
nS: Au, Cu, Al) Copper and aluminum activated sulfur
Zinc bromide / cadmium phosphor P22-GK4 [(Zn, C
d) S: Cu, Al], a red light emitting component phosphor
Rhodium-activated rare earth oxide-based phosphor, for example, chemical conversion opt
Nix P22-RE3 (Y₂O₂S: Eu), Euro
Pt-activated yttrium oxide phosphor P22-RE1 (Y
₂O _Three: Eu) etc. have been used for cathode ray tubes.
C, which has a short afterglow as a fluorescent substance
e, Ag activated YAP (YAlO_Three: Ce, Ag) or
Ce activated P47 (Y₂SiO_Five: Ce)
Can be. In addition, these phosphors have a filter effect.
Also used are those with attached pigments. With this kind of pigment
For example, for blue light emitting phosphor, cobalt aluminate is used.
And blue pigments such as ultramarine, and TiO for green light emitting phosphors₂-Z
Green pigment such as nO-CoO-NiO system, red color phosphor
There are red pigments such as red iron oxide and cadmium sulphate.
You. The size of the phosphor is about 1 to 20 μm
Is desirable.

As the ink for forming the black matrix, an ink containing a binder resin, a solvent, and a black pigment as main components is used. As the black pigment, those having light-shielding properties, sufficient blackness, and appropriate electrical conductivity are preferable,
For example, graphite is used. The particle size of the black pigment is 1μ
m or less is preferable. The same binder resin and solvent as the resin and solvent used for the fluorescent film forming ink can be used, and the ratio of the binder resin to the black pigment and the amount of the solvent used are also in the case of the fluorescent film forming ink. The same as is used.

As a method for producing the above-mentioned fluorescent film forming ink or black matrix forming ink, it can be easily produced using a generally known three-roll mill or ball mill. In addition, as a method of printing in a predetermined pattern on a substrate using a combination of inks of white or red, green, and blue phosphors having the above-mentioned configuration, and inks for forming a black matrix and index phosphors, The method is not particularly limited, and a screen printing method, a gravure printing method, a roll coating method, or the like can be used.
The generally known screen printing method is most suitable. Here, as an example, a method for forming a full-color three-color fluorescent film for an index tube will be described.

As an example of the order of printing, as shown in FIG. 1, a peeling layer is formed on an Al foil as a base material for thermal transfer, an index phosphor layer is formed on the Al foil, and a vapor deposition method or a metal foil film transfer is formed on the upper surface. To form an Al film, and then the index phosphor layer is located just at one position behind the black matrix between the blue-green phosphor layer or the blue-red phosphor layer or the green-red phosphor layer. After sequentially printing the three-color phosphor matrix so as to form a black matrix, an ink property or a plate pattern is designed to overlap the phosphor matrix to some extent, and a black matrix is overprinted. Further, an adhesive layer is provided on top of it to produce a transfer sheet for index tubes.

The release layer is laminated as needed for good transfer from the base material to the glass substrate during thermal transfer.
Similarly, the adhesive layer is appropriately used to increase the degree of adhesion to the glass substrate during thermal transfer. As the release layer, any wax or thermoplastic resin that has good releasability upon heating and has good thermal decomposability can be applied. Specifically, waxes such as various kinds of oxide waxes and polyoxyalkylene-modified waxes, and thermoplastic resins such as acrylic resins can be applied, and they can be formed by applying an organic solvent solution or an emulsion dispersion liquid. Thickness is 0.1-2
About μm is preferable.

As the adhesive layer, a resin having good adhesiveness to glass and good thermal decomposability, for example, acrylic resin, butyral resin, ethylene-vinyl acetate copolymer resin, urethane resin, cellulose resin, polyamide Any resin or the like can be applied, and it can be formed by applying an organic solvent solution or an emulsion dispersion. The thickness is preferably about 0.5 to 5 μm.

The thermal transfer sheet for forming a fluorescent film on which the above-mentioned fluorescent material layer is formed is brought into close contact with a glass substrate having a curvature such as a face plate of a cathode ray tube and is kept at 100 to 300.degree. By keeping the pressure at 1 to 10 kg / cm ² for 10 seconds to 3 minutes, it is possible to easily transfer to the glass substrate and form a fluorescent film having a smooth coated surface. Usually, the glass substrate on which the above-mentioned fluorescent film is formed is subjected to a baking treatment to give, for example, 200 to 600 ° C., preferably 30.
0 to 500 ° C., 20 minutes to 2 hours, preferably 30 minutes to 9
By baking for about 0 minutes, organic components are removed, and a pattern of green, blue and red phosphors can be formed.

The thermal transfer sheet for forming a fluorescent film and the method for forming a fluorescent film of the present invention can be widely applied as a technique for forming a fluorescent film on a glass substrate, and the above-mentioned ordinary cathode ray tube without the index fluorescent layer is used. When a phosphor screen is formed on a face plate of a tube, that is, a pattern of phosphor stripes formed in the order of R (red), G (green), and B (blue) is formed between black matrices. Can be used for. In addition, it can be applied to a monochromatic tube, a phosphor film for a lamp, and the like.

[0019]

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. Example 1 40 g of polyvinyl butyral resin (S-REC BX-1, manufactured by Sekisui Chemical Co., Ltd.) was added to 460 g of ethyl carbitol, and the mixture was heated and stirred to obtain a solution of 8% by weight of polyvinyl butyral resin. By using this as an organic medium and kneading with each phosphor, an ink for forming a fluorescent film was prepared. As a phosphor having a blue emission color, P22-B1 (ZnS: A manufactured by Kasei Optonix Co., Ltd.
17.5 g of the above organic medium was added to 50 g of g, Cl), premixed with a spatula, and kneaded and dispersed for 5 minutes using a three-roll mill to prepare a blue fluorescent film forming ink.

P22-GN (ZnS: Cu, Al) 50 manufactured by Kasei Optonix Co., Ltd. is used as a phosphor having a green emission color.
20 g of the above organic medium was added to g, premixed with a spatula, and then kneaded and dispersed for 5 minutes using a three-roll mill to prepare a green fluorescent film forming ink. As a phosphor having a red emission color, P22-RE3 (Y ₂ O ₂ S: Eu) manufactured by Kasei Optonix Co., Ltd. was added with 13.7 g of the above organic medium, and the mixture was premixed with a spatula, followed by a three-roll mill. Then, a red fluorescent film forming ink was prepared by kneading and dispersing for 5 minutes.

As an index phosphor having a short afterglow, KX-205A (YAlO ₃ : C manufactured by Kasei Optonix Co., Ltd.)
13.7 g of the above organic medium was added to 50 g of e, Ag), premixed with a spatula, and kneaded and dispersed for 5 minutes using a three-roll mill to prepare an index fluorescent film forming ink. Al with a thickness of 50 μm
(Linear expansion coefficient 2.9 × 10 ⁻⁵ , thermal conductivity (0 ° C.) 238W
・ M ^-1・ K ^-1 , heat capacity 2.4 J ・ K ^-1 ) An ink prepared by dissolving acrylic resin (LR396 made by Mitsubishi Rayon) dissolved in toluene as a release layer to a resin content of 8% on a foil is used. It was coated with a spinner and dried at 100 ° C. for 1 hour. The thickness of the release layer was 1 μm. Next, using a screen plate made of stainless steel 500 mesh, screen thickness 30 μm, emulsion thickness 10 μm, 45 μm by screen printing method so that the index phosphor layers are positioned at every other space between the phosphor matrix stripes.
A stripe-shaped index phosphor layer having a line width of 300 μm was formed and dried at 120 ° C. for 10 minutes to obtain an index layer having a film thickness of 5 μm.

Next, a metal Al layer is formed to a thickness of 10 by vacuum deposition.
The entire surface was covered with a thickness of 00 angstrom, blue phosphor ink was screen-printed with a line width of 100 μm at a pitch of 450 μm, and dried at 120 ° C. for 10 minutes. Next, using the same screen plate as described above, printing was carried out by sequentially shifting the screen by 150 μm each with green phosphor and red phosphor ink, and drying each time. The blue, green, and red phosphor layers are stripes each having a line width of 100 μm, and the film thickness is 7 μm.
Met.

Next, an ethylene-vinyl acetate copolymer resin (Evaflex 40X manufactured by Mitsui Polychemicals Co., Ltd.) was dissolved in terpineol to form an ink in graphite G manufactured by Hitachi Powder Metallurgy.
Using a black matrix ink in which P60S was dispersed with three rolls, screen printing was performed at a pitch of 150 μm with a line width of 50 μm so that the black matrix would be positioned exactly in the space between the phosphor matrices, and at 120 ° C. 10
By drying for a minute, a gap between the phosphor layers was filled and a black matrix layer having a layer thickness of 8 μm was obtained. Furthermore, on top of that, 2% polyvinyl butyral resin dissolved in a 1: 1 mixed solvent of isopropyl alcohol and methyl ethyl ketone (S-REC BL manufactured by Sekisui Chemical Co., Ltd.)
The S) solution was coated with a spinner and dried at 120 ° C. for 10 minutes to provide a 2 μm adhesive layer.

The above-mentioned transfer sheet is placed on a glass plate having a certain curvature, which is a face plate of a cathode ray tube, so that the adhesive layer adheres to the glass plate.
It was pressed for 1 minute under the conditions of 20 ° C. and 3 kg / cm ² . When the Al foil was peeled off, the pattern of the phosphor and the black matrix was clearly transferred onto the glass plate. The organic component was removed by baking the glass substrate at 450 ° C. for 30 minutes in the air atmosphere to form a phosphor pattern of three colors of green, blue and red.

As a result, a green, blue, and red phosphor stripe width was 100 ± 1 μm, and a uniform and highly smooth fluorescent film with a small pattern deviation was obtained. [Example 2] A base material used for a transfer sheet was made of copper having a thickness of 20 µm (coefficient of linear expansion 1.7 × 10 ^-5 , thermal conductivity (0 ° C) 403).
W · m ⁻¹ · K ⁻¹ , heat capacity 3.6 J · K ⁻¹ ) A phosphor pattern was formed by the same operation as in Example 1 except that the foil was changed. As a result, the green, blue, and red phosphor stripe widths were 100 ± 3 μm, respectively.
In the same manner as in No. 1, a fluorescent film with a small pattern deviation and a high surface smoothness was obtained.

Example 3 The thickness of the base material used for the transfer sheet
Only 30μm stainless steel (coefficient of linear expansion 1.6 × 10 ^-Five,heat
Conductivity (0 ℃) 24.5W ・ m^-1・ K^-1, Heat capacity 4J
K^-1) Change to foil and press temperature of hot press is 200 ℃
Fluorescence was obtained by the same procedure as in Example 1 except that
Formed body pattern. As a result, that of green, blue and red
The width of each phosphor stripe is 100 ± 5 μm.
Fluorescence with uniform and high surface smoothness
A film was obtained.

[Comparative Example 1] A base material used for the transfer sheet was a polyethylene terephthalate (linear expansion coefficient 180, thermal conductivity 2.5 to 3.4 W · m ⁻¹ · K ⁻¹ , heat capacity 2 J · K ⁻¹ ) film. A pattern of the phosphor was formed by the completely same operation as in Example 1 except that the above was changed. As a result, green, blue,
The width of each red phosphor stripe is 100 ± 15 μm
Although there was a large deviation of the pattern, a uniform and highly smooth surface fluorescent film was obtained.

Comparative Example 2 A phosphor pattern was formed by the same procedure as in Example 1 except that the substrate used for the transfer sheet was changed to polystyrene film. As a result, the width of each green, blue and red phosphor stripe is 10
The film thickness was 0 ± 20 μm, and the positional deviation of the pattern was large, and the phosphor film was non-uniform.

[0029]

According to the present invention, a fluorescent film is formed on a glass substrate, particularly a glass plate having a certain curvature, which is a face plate of a cathode ray tube, by using a fluorescent film forming ink that emits green, blue and red light. By using a specific base material to form the body matrix and the black matrix, it is possible to form a highly accurate and uniform fluorescent film with a small stripe line width and a small positional deviation, and to obtain a high quality product. A cathode ray tube can be formed, which is extremely advantageous industrially.

[Brief description of drawings]

FIG. 1 is an example of a thermal transfer sheet for forming a fluorescent film of the present invention.

Claims (12)

[Claims] 1. A linear expansion coefficient of 1 × 10 ⁻⁴ or less, a thermal conductivity of 10 W · m ⁻¹ · K ⁻¹ or more, and a heat capacity of 2 to 5 J · K ^−1.
On a sheet-shaped substrate that is, via a release layer, if necessary, at least a phosphor pigment, a heat-meltable binder resin,
And a fluorescent material layer containing a solvent, the thermal transfer sheet for forming a fluorescent film. 2. The thermal transfer sheet for forming a fluorescent film according to claim 1, wherein the sheet-shaped substrate is a metal foil. 3. The thermal transfer sheet for fluorescent film formation according to claim 1, wherein an adhesive layer is provided on the fluorescent material layer. 4. The fluorescent film forming thermal transfer sheet according to claim 1, wherein the phosphor layer has a black matrix and a cathode ray tube face plate pattern composed of three color phosphors of blue, green and red. A thermal transfer sheet for forming a fluorescent film, which is characterized in that 5. The thermal transfer sheet for forming a fluorescent film according to claim 1, wherein the phosphor layer is formed on an aluminum film. 6. The thermal transfer sheet for fluorescent film formation according to claim 5, wherein an aluminum film is formed on the index fluorescent material layer. 7. A linear expansion coefficient of 5 × 10 ⁻⁵ or less, a thermal conductivity of 10 W · m ⁻¹ · K ⁻¹ or more, and a heat capacity of 2 to 5 J · K ^−1.
On a sheet-shaped substrate that is, via a release layer, if necessary, at least a phosphor pigment, a heat-meltable binder resin,
And a fluorescent film-forming thermal transfer sheet on which a fluorescent material layer containing a solvent is formed is brought into contact with a glass substrate, and the thermal transfer head and the glass substrate are pressed from the back surface of the transfer sheet toward the glass substrate while pressing the thermal transfer head. A method for forming a fluorescent film, characterized in that the fluorescent film is thermally fused and transferred onto a glass substrate by relatively moving and. 8. The method for forming a phosphor film according to claim 7, wherein the glass substrate is a face plate of a cathode ray tube, and the phosphor layer on the sheet-shaped substrate is a black matrix and blue, green, and red. A method for forming a fluorescent film, characterized in that a pattern of a face plate for a cathode ray tube made of a color phosphor is formed. 9. The phosphor film forming method according to claim 7, wherein the phosphor layer is formed by using a screen printing method. 10. The fluorescent film forming method according to claim 7, wherein the sheet-shaped substrate is a metal foil. 11. The method for forming a fluorescent film according to claim 10, wherein the metal foil is aluminum, copper, or stainless steel, and the thickness of the foil is 2 to 1000 μm. 12. The method for forming a phosphor film according to claim 7, further comprising baking the phosphor layer transferred by thermal melting onto the glass substrate to remove the binder resin and the solvent. And a method for forming a fluorescent film.