JPH0212792A - Thin film el panel - Google Patents

Abstract

PURPOSE:To make moisture absorbing material free from omnipresence in a panel and a sufficient moisture preventing effect to be obtained by sealing up a film EL element with a back substrate or a solid or gel-like insulating material which contains a moisture absorbing material. CONSTITUTION:A film EL element is sealed up with a back substrate 8 and a solid or a gel-like insulating material 15 which contains a moisture absorbing material 11. It is preferable that the solid or gel-like insulating material 15 to be used is a liquid material which can be solidified or can gel, so that a moisture absorbing material 11 is made to be contained in the material or the EL element can be easily sealed up, and moreover, it is preferable that it has a good electric insulation ability and is free from generation of byproducts at the time of hardening; therefore, it is especially preferable that the insulating material 15 is epoxy resin or silicone resin. Furthermore, zeolite, silica gel, active almina, etc., is used for the moisture absorbing material which is contained in the insulating material 15. Thus, a film EL panel to which a sufficient prevention measures against moisture is provided can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thin film EL panel that emits EL (Electroluminescence) light upon application of an alternating current electric field.

(Prior Art) In general, a thin film EL panel is constructed by providing a transparent electrode 2 on a glass substrate 1, an EL thin film on the transparent electrode, and a back electrode 6 on top of the transparent electrode 2, as shown in FIG. Thin film E
The L element is connected to a back glass substrate 8 and silicone oil 7.
It has a sealed structure.

Furthermore, the above EL thin film is made of Mn-doped ZnS.
The EL light emitting layer 4 made of AβO, Zn5e, etc.
A double insulation structure sandwiched between a first dielectric layer 3 and a second dielectric layer 5 made of iO3 etc. has been developed, and a thin film EL panel obtained using this EL thin film has a dielectric strength of 1 light emission. It has excellent efficiency and operational stability. However, when such EL4m comes into contact with moisture,
There is a problem of brightness deterioration, and in thin AEL panels, moisture entering from the outside after sealing or moisture present in silicone oil causes brightness deterioration. Therefore, some kind of moisture-proofing measure is required for the EL thin film in the thin-film EL panel.

As the above moisture-proofing measures, conventional methods include (1) mixing a moisture absorbent such as zeolite into the silicone oil used for sealing; and (2) pasting a sheet coated with a moisture absorbent or a moisture absorbent processed into a sheet shape to the inside of the back substrate. methods are being used.

However, in method (1), zeolite is mixed in silicone oil but not dissolved, and if the panel is used in a stationary state for a long time, zeolite will be unevenly distributed. If this is unevenly distributed, a problem arises in that a sufficient moisture-proofing effect cannot be obtained. In method (2), the problem of uneven distribution of the hygroscopic agent does not occur because the hygroscopic agent is formed into a sheet. It is necessary to affix it to the inside of the back substrate, which makes the process extremely complicated.

(Problems to be Solved by the Invention) An object of the present invention is to provide a thin film EL panel that is provided with sufficient moisture-proofing measures and that can be obtained through a simple manufacturing process.

(Means for Solving the Problems) As a result of intensive studies to solve the above problems, the present inventors found that a solid or gel-like insulating material is used as a material for sealing a thin film EL element. It was discovered that a thin film EL panel with sufficient moisture-proofing measures could be obtained by this method, and the present invention was completed.

The present invention will be explained below based on the drawings. FIG. 1 is a diagram showing an example of a thin film EL panel of the present invention.

The thin film EL panel of the present invention includes a back substrate 8 and a solid or gel-like insulating material 15 containing a moisture absorber 11.
A thin film EL element is sealed with a thin film EL element.

The solid or gel insulating material used in the present invention is preferably a liquid material that can be solidified or gelled in order to incorporate a moisture absorber into the material or to facilitate sealing. Examples include thermosetting resins, photocuring resins, etc. These resins include butyl rubber resins, styrene butadiene rubber resins, chloroprene resins, acrylic resins, epoxy resins, Examples include fluororesins and silicone resins. Further, the above-mentioned material preferably has excellent electrical insulation properties and does not generate by-products during curing, and for this reason, epoxy resins and silicone resins are particularly preferred.

Furthermore, as the moisture absorber contained in the insulating material, zeolite, silica gel, activated alumina, etc. are used.

The thin film EL panel of the present invention can be prepared by, for example, mixing a moisture absorber,
By injecting the stirred insulating material before solidification or gelation through the injection hole 9 provided on the back substrate 8, then solidifying or gelling the insulating material, and sealing the injection hole 9, It can be obtained by sealing.

A thin film E formed by sealing a thin film EL element with a solid or gel-like insulating material containing the moisture absorber of the present invention.
In the L panel, the uneven distribution of moisture absorbers disappears after sealing, so that a sufficient moisture-proofing effect can be obtained.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these in any way.

EXAMPLES AND COMPARATIVE EXAMPLES As shown in FIG. 1, a large number of transparent electrodes 2 were arranged in parallel in strips on a glass substrate 1. Then, A I is applied on the transparent electrode 2.
2000 people formed the first dielectric layer 3 made of AFL 203, 9000 people formed the EL light emitting layer 4 made of ZnS with MnS added thereto, and 2000 people formed the second dielectric layer 5 made of AFL 203 on top of that. , are formed by a sputtering method, and then an A1 layer is formed to a thickness of 600 mm on the second dielectric layer 5.
After zero-person vapor deposition 1, the β layer was formed and arranged in a strip shape in a direction perpendicular to the transparent electrode 2, to form a back electrode 7.

Next, a back substrate 8 (thickness: 1.1 m) having injection holes 9 is
+) to the glass substrate 1 and transparent electrode 2 via the epoxy resin 12 to obtain a panel before injecting the insulating curable resin.

Insert the injection tube into the injection hole 9 of this panel, and place it in a vacuum dryer together with a container containing a liquid thermosetting resin (silicone resin, Silbot 500 manufactured by Dow Corning) mixed with zeolite. , use a vacuum pump to remove the air inside the vacuum dryer, the air inside the panel, and the air dissolved in the thermosetting resin, then return the pressure inside the dryer to atmospheric pressure, and inject the moisture absorbent through the injection tube. A thermosetting resin mixed with was injected into the panel.

After injection, the injection tube was removed, the panel was taken out, cleaned, and placed in the dryer again, where the thermosetting resin was heated and cured at 150°C for 30 minutes. After slow cooling, the area around the injection hole 9 of the panel is cleaned, and a piece of glass 13 is adhered with epoxy resin 12 so as to cover the injection hole 9 to seal it.

A panel was prepared according to the above method, placed in a constant temperature and humidity chamber, and subjected to a life test in an atmosphere at a temperature of 70° C. and a relative humidity of 80%. In addition, a panel made using the same procedure was injected with only a curable silicone resin, cured, and sealed, and then placed in the same constant temperature bath so that the results could be compared.

As a result of the experiment, only 30% of the panels filled with only curable silicone resin maintained 90% or more of their initial brightness during a 10,000-hour life test. On the other hand, it was observed that all the panels sealed with a curable silicone resin mixed with a moisture absorbent maintained 90% or more of their initial brightness.

(Effects of the Invention) As described above, the thin-film EL panel of the present invention has no uneven distribution of moisture absorbers in the panel, so that a sufficient moisture-proofing effect can be obtained. Furthermore, since there is no need for processing the moisture absorber used, it can be obtained through a simple manufacturing process.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a thin film EL panel of the present invention. FIG. 2 is a diagram showing a conventional thin film EL panel. In the figure 1...Glass substrate 2...Transparent electrode 3...
First dielectric layer 4...Light emitting layer 5...Second dielectric layer 6...Back electrode 7...Silicone oil
8... Rear substrate 9... Injection hole 10...
・Epoxy resin 11...moisture absorber 12...
・Epoxy resin 13...Glass piece 14...
- A1 Alloy 15: Indicates a solid or gel-like insulating material.

Claims (1)

[Claims] (1) A thin-film EL panel characterized in that a thin-film EL element is sealed with a solid or gel-like insulating material containing a rear substrate and a moisture absorber.