JPS60264094A - Electroluminescent element - 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] [Field of Application of the Invention] The present invention relates to an electroluminescent device (hereinafter referred to as E L
D), and particularly relates to the moisture-proof structure of ELDs.

[Background of the invention]

ELD is a device that utilizes the light emitting phenomenon caused by applying a voltage to a light emitting layer such as ZnS in which manganese is diffused.
known as.

FIG. 1 is a cross-sectional view of a conventional flexible dispersion type ELD.

In FIG. 1, 1 is a light emitting section, and this light emitting section 1 includes a lower electrode 21, a light emitting layer 3. It is formed with a three-layer structure of transparent electrodes 4.

The lower electrode 2 is formed of, for example, metal powder such as silver dispersed in an organic polymer or inorganic binder, or metal foil or thin metal film of aluminum, copper, or the like.

The light-emitting layer 3 is formed by dispersing a phosphor powder in which ZnS is doped with an activator such as copper or manganese and an activator such as chlorine in an organic polymer binder. There are also those using elements such as -valent metals, transition metals, etc.

The transparent electrode 4 is formed of a thin film of metal oxide such as IruOz or Snow, a thin film of gold or palladium, or a thin film of metal such as aluminum or copper in which small mesh-like holes are formed.

A moisture-proof water trapping layer 5 made of a hygroscopic film 5 is provided below the lower electrode 2 of the light emitting part 1 to form a four-layer structure.
This four-layer structure light emitting part 1 and moisture-proof water trapping layer 5 are combined with a heat-melting film 6 such as polyenalene and fluorine 1! Protective sealing material (
A groove-proof structure was obtained by applying a seal A-9 using a heat roll, adhesive, etc. to the protective sealing materials 8 and 8.

However, a small amount of moisture enters the spaces 10a, 10b from the surfaces of the security sealing materials 8, 8, the seal portions 9 and 4 (not shown), and the moisture-proofing effect is not sufficient.

In addition, the hygroscopic film of the moisture-proof water-absorbing layer 5 shows signs of water expansion starting temperature, and when the atmospheric humidity is high, hot water is easily released.
As a result, internal humidity tends to increase.

For this reason, it is also known that the moisture-proof water extraction layer 5 is provided with an inorganic drying smoke agent such as zeolite or calcium oxide, which has a high water initiation depth of 8.4 degrees, or in combination with a hygroscopic film. However, it is impossible for the moisture-proof water absorption layer 5 to absorb all of the infiltrated moisture because the moisture absorption rate of the water absorption layer, the moisture absorption layer, etc. are finite, and excess moisture enters the luminescent layer 3. This moisture has the disadvantage of adversely affecting the light emitting life of the ELD.

[Purpose of the invention]

The present invention aims to eliminate such conventional drawbacks,
The purpose of this is to reduce the moisture inside the ELD as much as possible, and also to prevent moisture from entering the light emitting part, thereby extending the light emitting life.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention provides a moisture absorbing layer around the light emitting part to absorb moisture and prevent it from penetrating into the light emitting layer.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

2 to 4 are cross-sectional views of an ELD according to an embodiment of the present invention, FIG. 5 is a developed view of the protective sealing material of FIG. 4, and FIG. 6 is a cross-sectional view of an ELD according to another embodiment. It is.

In FIG. 2 to FIG. 6, reference numerals 1 to 10b indicate the same parts as the conventional one. Reference numeral 11 denotes a moisture absorbing layer provided around the light emitting part 1, and this moisture absorbing layer 11 is formed of desiccant powder such as zeolite, silica gel, molecular sieve, calcium oxide, etc., and a binder such as polyvinyl alcohol and various celluloses.

In such a structure, the conventional one-bow LD shown in Figure 1 and the H of the present invention shown in Figures 2 to 4 and VC H6.
The difference in the LD is that in the one shown in FIG. 1, a moisture-proof water extraction layer 5 is arranged in parallel under the lower electrode 2, whereas in the one of the present invention, a moisture-proof water extraction layer 5 is arranged in parallel around the light emitting part 10. This is because the moisture absorption layer 11 is provided.

In other words, the one in Fig. 2 is the IU11 surface of one light emitting section l.

A moisture absorption layer 11 is filled between the seal portions 90.

By covering the side surface of the light-emitting part 1 with the moisture-absorbing layer 1.1 in this way, the moisture that has entered from the sealing parts 9, 9 is absorbed immediately by the moisture-absorbing layer 11, so that the moisture is directly transferred to the light-emitting layer 3. Infiltration can be prevented.

In addition, the ELD shown in Fig. 2 was operated at 40°C and relative humidity of 90~90°C.
When we conducted a continuous lifespan test of 50H4 at 100V in a 95% atmosphere, the half-life of the luminescence intensity reached 1800 hours, and the luminescence lifespan was extended by about 20% compared to the one from t4X. Ta.

The one in FIG. 3 shows another embodiment, which is different from the one in FIG. 2. The difference is that in the one in FIG. In contrast, the one in Figure 3 has a moisture absorbing layer 1 on the i side of the light emitting 7-rule 1.
1, and the periphery of the light emitting part 10 is covered with this absorber layer 11.

In other words, the one in Figure 3 is l11111fu of light emitting part 1.
The K absorption layer 11 is made of Kl cloth with a thickness of about 0.1 to 1 bead, and the applied moisture absorption layer 11 prevents moisture from entering the light emitting layer 3.

When the ELD shown in Figure 3 was subjected to a continuous life test under the same conditions as the one in Figure 2, the half-life of the luminescence intensity was over 2000 hours, which was 3 times shorter than that of the conventional one. The lifespan of the luminescent light was extended by more than a certain amount.

The ones in FIGS. 4 and 5 show other actual hjt examples, and the difference from the ones in FIGS. 2 and 3 is that the moisture absorption layer 11 is reinforced in the sealing parts 9, 9, Place the protective seal on the heat-melting film 6 at the inner 111C position of the film 8 as shown in Figure 5. n: Iso1
1 is shaped like a frame III, 74ζ, and these protective sealing materials 8 are placed inside each other, and the seal portions 9, 9 are sealed as shown in FIG.

In this way, the periphery of the light emitting part 1 is surrounded by a frame-like layer K'g, which is covered with an interfacial layer 11 to prevent moisture from penetrating into the light emitting part 3.

Still another embodiment is shown in No. 61 No. 1, and the difference from the one in FIG. The moisture absorbing layer 11 is used in combination with the moisture absorbing layer 11, and the moisture absorbing layer 11 is connected to the water extraction layer 5 through the formation of the moisture absorbing layer 11.

Note that the ELD shown in Figure r414 and Figure 6 is
Nu I%m, 3 Continuous life test under the same conditions as Lsl? When it became 1, W, the life extension similar to the one in figure 2 was 1.

Above, in the embodiments of the present invention, cases were explained in which the embodiments shown in FIGS. 2 to 6 were implemented individually, but the present invention is not limited to these embodiments. It is also possible to combine them as appropriate.

By using the embodiments in this way, it is possible to further prevent moisture from entering the light emitting section 1, and furthermore, it is possible to prevent moisture from entering from a lead wire pull-out portion (not shown) or the like.

〔Effect of the invention〕

The present invention is achieved by providing a hygroscopic layer around the light emitting part 9.
．． Moisture inside the ELD is reduced, preventing moisture from entering the light emitting part and extending the light emitting life.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional ELD, Figures 2, 3, and 4.
6 and 6 are cross-sectional views of an ELD according to an embodiment of the present invention, and FIG. 5 is a developed view of the Hoki sealing material of the fourth embodiment. 1... Light emitting part, 2... Lower electrode, 3...
...To the source mail ■4...Toru 1iti, s...
... Purulent sealing material, 9. Hitting/sole part, 11...
...Moisture absorption 114゜Representative Masujishi Takeshi Butsuji DepartmentFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 5 3 2

Claims (1)

[Claims] A light-emitting part in which a light-emitting layer is provided between a lower electrode and a transparent electrode is covered with a protective sealing material, and the light-emitting part is sealed against moisture by sealing the hairon sealing material together, in which a light-emitting part is provided around the light-emitting part. An electroluminescent element characterized by being provided with a latent absorption layer.