JPH0330290A - Electroluminescence lamp - Google Patents

Abstract

PURPOSE:To restrict the lower of luminance to be caused by the deterioration of a light emitting layer and reduce the demand by including the specified refined cyanoethyl saccharose in a binder forming the light emitting layer and an insulating pressure-proof layer. CONSTITUTION:An insulating pressure-proof layer and a light emitting layer are formed by using a binder including 1-50weight% of cyanoethyl saccharose of which dielectric dissipation factor tan delta is less than 0.01. The dielectric dissipation factor tan delta of cyanoethyl saccharose is less than 0.01, but desirable dielectric dissipation factor tan delta is less than 0.005. The lower of the luminance to be caused by deterioration of the light emitting layer is thereby reduced, and the demand is reduced to prolong the lifetime of a battery of a portable equipment.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an electroluminescent lamp (hereinafter referred to as E
(referred to as L lamp).

[Conventional technology]

Most of today's portable computers and word processors use liquid crystal displays, which use E as backlighting.
Uses an L lamp, and uses dry batteries or nickel batteries as a power source.
Many use cadmium batteries, and EL is a backlight source.
The lamp is the main power consumption source. Therefore, especially in the above-mentioned portable equipment, it is extremely required that the power consumption of the EL lamp be low.

By the way, the general structure of an EL lamp will be briefly described with reference to FIG. 2. It has a structure that is protected from moisture by upper and lower moisture-proof films 1 and 1'. A back lead electrode 2, a back electrode N3, an insulating voltage layer 4, a light emitting layer 5, a front lead electrode 6, and a transparent electrode layer 7 are provided in this order on the moisture-proof film l' on the back side.

The dielectric strength voltage N4 and the luminescent layer 5 are determined by separating a ferroelectric insulator and a phosphor into various binder resins.
Some use a binder containing cyanoethylated sucrose with a high dielectric constant (about ε-40) so that a strong electric field can be applied to obtain high luminance.

[Problems to be Solved by the Invention] However, although cyanoethylated sanorose is more effective in increasing brightness than ordinary binders, it has the following problems.

First of all, cyanoethylated saccharose itself contains many impurities (alkali metal ions in most cases), which is a factor that accelerates the deterioration of the luminescent layer, leading to a rapid decline in luminance.

Secondly, due to impurities in cyanoethylated saccharose,
As the dielectric loss tangent tan δ increases, the power consumption also increases, which is inconvenient because the life of the heavy battery in the portable i-device is shortened.

Therefore, it is an object of the present invention to provide an EL lamp that solves the above two problems.

[Means to solve the problem]

As a result of our intensive research, the present inventors found that the dielectric loss tangent tanδ
1 cyanoethylated pork loin with 0.01 or less
We have discovered that the above object can be achieved by forming the dielectric strength layer and the light emitting layer using a binder containing ~50% by weight,
We have now completed the present invention. The cyanoethylated sucrose used in the present invention has a dielectric loss tangent tan δ of 0.01 or less, preferably 0.01.
0 0 5 or less. Incidentally, the dielectric loss tangent tan δ of ordinary unrefined saccharose is about 0.02 or more.

An example of the method for preparing such cyanoethylated sassocallose will be described. As long as the dielectric loss tangent tan δ is 0.01 or less,
It is not limited to this.

With cyanoethylated sucrose a. ? g agent, preferably acetone, and the resulting solution is combined with water and stirred thoroughly. Impurities in sa-nocalose are eluted into water by stirring. After the mixed solution is left to stand and the solution is separated into a water component layer and a binder component layer, a certain layer of the binder is separated. By vacuum-drying the binder component layer and evaporating moisture in the component layer, purified cyanoethylated sucrose having a dielectric loss tangent tan δ within the above-mentioned specific range can be obtained.

The cyanoethylated sasocallose that is the starting material is not particularly limited, and commercially available ones are sufficient, and specific examples include A-04 manufactured by Mitsubishi Kawi Corporation.

The solvent is not particularly limited as long as it is substantially inert and can dissolve cyanoethylated sucrose, and examples include acetone, methyl ethyl ketone, dimethylformamide, acetonitrile, methylene chloride, and chloroform.

It is preferable to use highly purified solvents. Furthermore, when the cyanoethylated sucrose specified in the present invention is used as a binder, it is usually preferable to mix components other than saccharose such as cyanoethyl pullulan and cyanoethyl cellulose with the cyanoethylated saccharose. In that case, the cyanoethylated sucrose is usually blended in an amount of 1 to 50% by weight, preferably 5 to 30% by weight.

Furthermore, the thickness of the insulating voltage layer and the light emitting layer made of a binder containing cyanoethylated sucrose naturally differs depending on the form of the EL lamp, its use, etc.;
50 μm, and the light emitting layer is 10 to 100 μm.

[Example] The EL lamp of the present invention will be described below based on an example. The Snake L lamp of the present invention has a dielectric loss tangent tan δ as described above.
1 to 5 cyanoethylated saccharose with 0.01 or less
It is characterized by the use of a binder containing 0% by weight, and other than that, the external shape and internal structure are basically the same as conventional ones. For example, the structure is substantially the same as that of the normal EL lamp shown in They may be the same.

Figure 1 shows its cross-sectional structure, showing the upper and lower moisture-proof films 1,
1' is completely sealed, and there is a moisture-proof film 1 on the back side inside.
A back electrode layer 3, an insulating voltage layer 4, a light-emitting layer 5, and a light-transmitting electrode layer 7 are provided in this order on the substrate. It goes without saying that the vA edge withstand voltage layer 4 and the light emitting layer 5 are made using the above-mentioned binder.

Next, since the EL lamp of the present invention uses a binder containing the above cyanoethylated saccharose (dissipation tangent tan δ: 0.01 or less), it is possible to overcome the conventional cyanoethylated sucrose (dissipation tangent tan δ: 0.02 or less). Based on Examples and Experimental Examples, it will be explained whether the present invention is superior in suppressing reduction in emission brightness and lowering power consumption than an EL lamp using a binder containing the above-mentioned binders.

Example 1 Mitsubishi Kasei A-04: Cyanoethylated sucrose 5
0g to 50% acetone? Understood, then? Add 3 ml of liquid to water
0 0 ml and stir thoroughly. After stirring, the mixed solution is left to stand for about 12 hours until it separates into a water component layer and a binder component layer. Thereafter, a certain layer of the binder is separated and dried under vacuum. Obtained dielectric loss tangent tanδ=0
．． A binder (the content of cyanoethylated saccharose is 20% by weight) was prepared by mixing the cyanoethylated saccharose of No. 01 with other binders such as cyanoethylated pullulan and cyanoethylated cellulose, and this binder was used to form the light-emitting layer and the insulating voltage layer. I prepared a well-prepared EL lamp.

Examples 2 to 3 In the same manner as in Example 1, a binder was prepared by mixing cyanoethylated sasocallose having the dielectric loss tangent tan δ shown in Table I with cyanoethylated pullulan and cyanoethylated cellulose as other binder components. We prepared an EL lamp with a light-emitting layer and a dielectric strength layer.

Comparative Examples 1 to 3 As usual, the dielectric loss tangent tan δ listed in Table I
A binder was prepared by mixing cyanoethylated saccharose having the following properties with cyanoethylated pullulan and cyanoethylated cellulose as other binders, respectively, and an EL lamp was prepared in which a light-emitting layer and an insulating voltage layer were formed using this binder.

Experimental Example 1 The luminance and power consumption of each EL lamp obtained in the above Examples and Comparative Examples were measured under the following measurement conditions, and the results are shown in Table 1.

Measurement conditions (emission brightness) lOOv14. under an atmosphere of 20'C and 65% RH. O
The initial luminance (cd/bo) when driven at OHZ and the luminance (cd/bo) after continuous lighting for 1000 hours under the same conditions are shown.

(Power consumption) The power consumption per unit area of the lamp (mW/cd) when driven at 100V and 400Hz is shown.
(The following is a blank space) [Table I] [Effects of the Invention] Since the EL lamp of the present invention is effective as described above, it exhibits the effects as described below.

The dielectric loss tangent ta of the binder forming the light emitting layer and the dielectric strength layer is
nδ:O. By containing 1 to 50% of barycrystalline cyanoethylated saniroku loin produced by Tei with an OX or less, it is possible to suppress a decrease in luminance due to deterioration of the light emitting layer, and at the same time, power consumption is also reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of the EL lamp of the present invention, and FIG.
The figure is a schematic exploded perspective view showing the general structure of an EL lamp. 1, 1': Protective crystal finolem 3: Back electrode layer 4: Insulating voltage layer 5: Luminescent layer 7: Transparent electrode layer Fig. 1 Fig. 2

Claims (1)

[Claims] The binder resin forming the evergreen breakdown voltage layer and the light emitting layer of the electroluminescent lamp has a dielectric loss tangent tan δ: 0.
1. An electroluminescent lamp comprising 1 to 50% by weight of cyanoethylated sucrose of 0.01 or less.