JPS61131394A - Manufacture of dispersion type el - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a dispersed type GL (electroluminescent device) with a long life.

[Technical background of the invention]

Dispersed EL is generally a light-transmitting electrode placed on a light-transmitting substrate in dry nitrogen with a dew point of 6° C. (partial pressure 7 anHg) or less.

A light-emitting layer, an insulating layer, and a back electrode are sequentially laminated and dried under heat in an inert gas to form a light-emitting body, which is then covered and sealed with glass or synthetic resin in the same atmosphere.

[Problems with background technology]

In other words, the time taken for the luminance to decrease by half was extremely variable, and the life span was not sufficient.

[Purpose of the invention]

The purpose of the present invention is to provide a method for producing a dispersed KL that has a long life and is stable.

[Summary of the invention]

The light emitter has a dew point of -30°C (water vapor partial pressure 0.3 amHg)
By sealing in the following dry inert gas atmosphere,
This prevents the light emitter from absorbing moisture.

[Embodiments of the invention]

The present inventors came up with the idea that the lifespan of a dispersed EL is correlated with the amount of water absorbed by the phosphor during sealing, and as a result of various research,
It was discovered that the amount of water absorbed is related to the absolute humidity in the atmosphere. In other words, zinc sulfide (Zn8), which is a luminescent material, is stable in a (humid) atmosphere with a dew point higher than 130°C (partial pressure of water vapor 0.3 uHg), containing some crystal water; lower than -30℃ (dry)
'W, anhydrous substances are stable in an ambient atmosphere, and it has therefore been assumed that if the absolute humidity in the atmosphere is kept at a dew point of -30°C or less, it will be stable and have a long life.

Hereinafter, the details of the present invention will be explained with reference to Examples.

First, as shown in Figure 1, transparent electrodes (2) made of indium oxide and tin oxide, zinc sulfide (Z
n8) A light emitting layer (3) made of a phosphor and an insulating layer (4) made of barium titanate are sequentially laminated, heated and dried, and then aluminum is deposited on this laminated layer to form a back electrode (
5) to constitute a light emitting body (6). Then, as shown in FIG. 2, it was placed in a work box (7) through which dry nitrogen gas with a dew point of 130° C. or less was passed.

Sealing films (8) made of 37 fluorochloroethylene ε are layered on the top and bottom of the light emitting body (6), and heated with a heat roller (9).

(9) etc. to seal. Then, II! is sealed as shown in FIG. L is obtained.

In this manufacturing method, the dew point inside the work box (7) is -30°.
Since dry nitrogen gas of C or less is flowing, the luminescent layer (3
) does not newly absorb moisture, and even if it contains some moisture before being stored in the work box (7), it will be released during storage and will not be sealed. At that time, K is anhydrous. In addition, the base (1)
and other layers (2), (3), (4), (
Even if a very small amount of water is adsorbed on 51, it will be dehydrated until it is in equilibrium with the atmosphere. Therefore, after encapsulation, the zinc sulfide phosphor does not absorb moisture from other layers. Therefore, the zinc sulfide phosphor in the EL does not deteriorate due to moisture, and there is little reduction in brightness even after long-term use.

Next, the correlation between the degree of dryness of the dry nitrogen gas in the sealing process shown in FIG. 2 and the lifespan was investigated, and the results are shown in FIG. In the figure, the horizontal axis shows the dew point of nitrogen gas in degrees Celsius, and the vertical axis shows the brightness half-life time in hours, and the curves show the correlation. As is clear from this figure, the luminance half-life time changes discontinuously before and after the nitrogen gas dew point reaches 130°C, proving that the lifetime changes suddenly due to the aforementioned discontinuity in the crystal water content. Ta.

If you are concerned about the ability of the sealing film (8) to prevent moisture from penetrating, that is, its moisture barrier properties, cover and seal the 1 light emitting body (6) with a highly moisture barrier material such as a nylon stamp, and then It is sufficient to seal with a sealing film (8), in this case,
The moisture barrier coating may be performed in dry nitrogen gas with a dew point of -30°C or lower.

Furthermore, although nitrogen was used as the atmospheric gas in the above-mentioned embodiments, the present invention is not limited to this, and it goes without saying that argon may also be used. Further, the material to be coated and sealed is not limited to synthetic resin, but may be glass. Further, the substrate may be diffusely transparent. Furthermore, in the present invention, only the sealing step may be performed in a dry atmosphere with a dew point of 130° C. or less.

〔Effect of the invention〕

The method for producing a dispersed EL according to the present invention is to laminate a light-emitting layer of a light-transmitting electrode, an insulating layer, and a back electrode in sequence on a light-transmitting substrate in a dry inert gas atmosphere with a dew point of 130°C or less. Since it is coated and sealed with glass or synthetic resin, the phosphor in the light emitting layer can be sealed in an anhydrous state, which dramatically reduces brightness loss even after long-term use, resulting in a long life. Ta.

[Brief explanation of drawings]

Figures 1 to 3 show an example of the drawing method for a distributed EL according to the present invention in the order of steps (to the explanation shown), and Figure 4 shows the correlation between the dryness of the atmospheric gas and the lifespan in this example. This is a graph. (1)...Substrate (2)...Transparent electrode (
3)...Light emitting layer (4)...Insulating layer (5)
・・Backside electrode (6)・・Light emitter (8)・・Sealing film agent Patent attorney Inoue - Male 1st figure 2nd figure 3 figure 4th figure 0 -IO-20-,30-Kl -,! ;0□
Dew odor (°C)

Claims (1)

[Claims] A light-emitting body consisting of a light-transmitting electrode, a light-emitting layer, an insulating layer, and a back electrode laminated in sequence on a light-transmitting substrate is sealed by covering it with glass or synthetic resin in a dry inert gas atmosphere with a dew point of -30°C or less. A method for manufacturing a dispersed EL, characterized in that: