JPS5937555B2 - Manufacturing method of double-sided electroluminescent lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a double-sided electroluminescent lamp, particularly an electroluminescent lamp in which a phosphor-emitting layer is interposed between transparent conductive substrates or films.

Double-sided electroluminescent lamps use both sides as light-emitting surfaces.
It can be obtained by bonding two ordinary electroluminescent lamps with one side as a light-emitting surface and pasting their non-light-emitting sides together, or by forming light-emitting layers on both sides of a common electrode substrate, but it is essentially a separate electroluminescent part. Since it uses , it is structurally complex and expensive.

It has also been proposed to obtain a double-sided electroluminescent lamp by forming transparent electrodes on both sides of the light emitter, but it is difficult to form the light emitter and one transparent electrode body, making it difficult to produce a practical and economical method. was difficult. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to overcome the above-mentioned drawbacks and to provide a new and improved method for manufacturing a double-sided electroluminescent lamp.

According to the present invention, a thin film containing a high dielectric constant binder is formed on the conductive side of a pair of transparent conductive substrates or films,
At least one of the thin films is provided as a luminescent thin film with phosphors dispersed therein.

All of these thin films are high dielectric layers, and if they do not contain a phosphor, they become light-transmitting thin films. A pair of transparent conductive substrates each having a predetermined thin film formed thereon are heat-pressed at a temperature higher than the plasticization temperature of the thermoplastic film, with a thermoplastic film interposed between them, and bonded to each other by thermocompression bonding to form a pair of transparent conductive substrates. A double-sided light emitting type electroluminescent lamp is manufactured in which a light emitting layer including a light emitting thin film having at least a phosphor is interposed between substrates. That is, a double-sided light-emitting type electroluminescent lamp is produced by bonding the light-emitting conductive films or the light-emitting thin film and the dielectric thin film formed on both transparent conductive substrates with a molten thermoplastic film by pressing at a temperature at which the thermoplastic film melts. Manufacture. Specifically, polyvinylidene fluoride film, which is a high dielectric material, is used as the thermoplastic film, and is used as a thin film of about 10 μm.

- On the other hand, for the thin film formed on the conductive side of each transparent conductive substrate, cyanoethyl cellulose with a high dielectric constant is used as a binder, and a luminescent thin film with a phosphor dispersed in this binder or barium titanate dispersed in the binder as necessary. It is deposited as a transparent, highly dielectric thin film. Therefore, such a thin film is prepared by printing a vehicle in which cyanoethyl cellulose is dissolved in its solvent such as acetone or acetonitrile, either as is or as a suspension in which phosphor or barium titanate is dispersed, on the conductive side of a transparent conductive substrate. is formed by adhering to it. A transparent conductive substrate on which a thin film has been formed in advance is bonded together by thermocompression with a thermoplastic film in between, and then the whole is tightly sealed with a well-known moisture-proof outer cover to obtain a double-sided light-emitting type electroluminescent lamp. Here, the thermoplastic film effectively diffuses into both the light-emitting thin film and the dielectric thin film on the uneven surface formed by the binder on each transparent conductive substrate in the thermocompression bonding process, thereby improving the adhesion between the two. It penetrates into the pinholes of the thin film and improves its density. Therefore, the bond between the two after thermocompression bonding becomes extremely dense, increasing the brightness of the electroluminescent lamp and improving the luminous efficiency. Furthermore, when forming one of the thin films as a light-transmitting dielectric thin film doped with barium titanate, its light transmittance or reflectance can be adjusted by adjusting the amount of barium titanate powder, and light emission from each transparent electrode surface side can be adjusted. The intensity can be controlled. Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a double-sided emitting type electroluminescent lamp manufactured according to the present invention, and FIG. 2 is a partial sectional view of the manufacturing process of the electroluminescent lamp of FIG. 1.

In FIG. 1, each electroluminescent lamp 1 has a transparent conductive film 2.
, 3, a light-emitting layer 8 is interposed between a pair of transparent conductive films 6, 7 of transparent sheets 4, 5 having mesh leads 9, 10 drawn out from the current collecting portion of the conductive film of each transparent conductive film 6, 7. It is configured by leaving an external lead-out portion and surrounding and sealing it with a moisture-proof outer skin 11. Here, the transparent conductive film 6,
For 7, a film is used in which a conductive film is formed by vapor depositing indium oxide on a resin sheet of about 80 μm, and for outer skin 11
was formed by hot pressing a moisture-proof resin film of about 200μ. On the other hand, the light-emitting layer 8, which is a feature of the present invention, is formed by bonding a light-emitting thin film 12 and a light-transmitting dielectric thin film 13 with an adhesive layer 14 of thermoplastic film material. Manufactured. FIG. 2 shows the components necessary to form the light emitting layer 8 between the pair of transparent conductive films 6 and 7 shown in FIG. The components of the luminescent thin film 12 formed, the transparent dielectric thin film 13 formed by silk screen technique on the conductive film 3 side of the other transparent sheet 5, and the thermoplastic film 15 interposed between these thin films are shown. Each thin film 12
, 13 used cyanoethylcellulose with a high dielectric constant as a binder, and dissolved it in Akoton.
% (wt) concentration vehicle. That is,
The light-emitting thin film 12 is prepared by preparing a suspension in which the vehicle and the phosphor are dispersed in a weight ratio of 5:8, coating it on the conductive film 2 side of the transparent sheet 4 by a screen printing method, and drying it for about 30 to 30 minutes.
A thin film with a thickness of 40μ is used. On the other hand, the transparent dielectric thin film 13
The conductive film 4 of the transparent sheet 5 is prepared using the above-mentioned vehicle alone or as a suspension of barium titanate powder dispersed therein.
It is applied to the sides using screen printing and dried to form a thin film of several microns or less. Next, a thermoplastic film 15 made of a thin sheet of polyvinylidene fluoride, which is a high dielectric material, is placed between each of the thin films 12 and 13, and both transparent sheets 4 and 5 are overlapped and properly pressed from the outside, and the thermoplastic film is 15
Heat to 200°C above the plasticizing temperature. The thin film 15 of about 10 μm is melted by heat and pressure bonding, effectively spreads over the relatively rough and uneven thin films 12 and 13, and penetrates into the pinhole portion to densify and bond the two. Therefore,
The film 15 is deformed and fills the voids in the thin film containing the phosphor, and constitutes a part of the luminescent layer 8 as an adhesive layer 14 existing between the thin films 12 and 13 shown in FIG. FIG. 3 shows another embodiment of the present invention, in which the polyvinylidene fluoride film of the thermoplastic film 15 is interposed between a transparent conductive film 19 in which a luminescent thin film 16 is adhered to the conductive film 18 side of a transparent sheet 17. This shows the state where it is placed.

In this state, when the three are superimposed and thermocompressed, a light emitting layer having a structure in which a light emitting thin film 16 containing a double phosphor is bonded between a pair of transparent conductive films 19 by a polyvinylidene fluoride adhesive layer is formed. It is formed. Here, each light-emitting thin film 16 is applied thinner than the light-emitting thin film 12 in the case of FIG. 2, and is made into a relatively dense light-emitting layer with a uniform thickness, thereby improving the light-emitting efficiency from both sides. Of course, barium titanate can be added to each light-emitting thin film 16 to improve the light-emitting characteristics, and furthermore, a polypropylene film may be used as the thermoplastic film 15. In the above embodiments, a resin sheet material was used as the substrate for the transparent conductive film, but a glass plate formed with a transparent conductive coating may also be used as the transparent conductive substrate.

iAlso, since the high dielectric constant material such as barium titanate added to the light-transmitting dielectric thin film is a factor that determines the light-transmitting property for one light-emitting surface and the reflectivity for the other light-emitting surface, It can be used as an adjustment means to determine the required light emission ratio.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a double-sided electroluminescent lamp manufactured according to the present invention, FIG. 2 is a partial cross-sectional view during the manufacturing process for explaining an embodiment of the present invention, and FIG. FIG. 3 is a sectional view showing another embodiment of the invention. 1...Double-sided emitting type electroluminescent lamp, 2,3...
...Conductive film, 4,5...Transparent sheet, 6,7,
19...Transparent conductive film, 8...
Light-emitting layer, 12, 16... Light-emitting thin film, 13...
...Transparent dielectric thin film, 15...Thermoplastic film.

Claims (1)

[Scope of Claims] 1. A light-emitting thin film including a phosphor and a binder applied to the conductive side of a first transparent conductive substrate, and a dielectric film including a binder applied to the conductive side of a second transparent conductive substrate. Between the thin film,
A double-sided light-emitting type electroluminescent lamp characterized in that a thermoplastic film is disposed and heat-pressed at a temperature equal to or higher than the plasticizing temperature of the thermoplastic film to bond the luminescent thin film and the dielectric thin film via the thermoplastic film. manufacturing method. 2. The method for manufacturing a double-sided light emitting type electroluminescent lamp according to claim 1, wherein the dielectric thin film is a light-transmitting thin film containing a high dielectric material. 3. The method for manufacturing a double-sided light emitting type electroluminescent lamp according to claim 1, wherein the binder is cyanoethylcellulose. 4. The method for manufacturing a double-sided electroluminescent lamp according to claim 1, wherein the dielectric thin film is a light emitting thin film containing a phosphor. 5. The method for manufacturing a double-sided electroluminescent lamp according to claim 1, wherein the thermoplastic film is polyvinylidene fluoride or polypropylene.