JPH09232076A - El lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide higher brightness, reduce microscopic nonuniformity in brightness, and prevent reduction in brightness in high humidity in a distributed EL lamp by sandwiching a light emitting body layer and a dielectric layer between conter electrode layers on an insulating transparent film. SOLUTION: Insulating resin 9 to constitute a light emitting body layer 3 is formed of vinylidene fluoride resin or vinylidene fluoride copolymerization rubber, and when ultra-particulate high dielectric powder 8 is dispersed in the insulating resin 9, the light emitting body layer 3 increases in a dielectric constant, and light emitting brightness is enhanced, and at the same time, microscopic nonuniformity of brightness is improved because of light diffusion of the ultra-particulate high dielectric powder 8, and since the insulating resin 9 is a fluorine type, an EL lamp which is hardly influenced by an environmental atmosphere such as high humidity can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EL lamp used in a lighting section of various electronic devices.

[0002]

2. Description of the Related Art In recent years, small transformers and IC drive inverters have been developed, and as a backlight for liquid crystal displays and switches of various electronic equipment such as communication equipment, video equipment and audio equipment, they are thin and flat. The demand for EL lamps that emit light is increasing.

Dispersion type EL lamps have heretofore been formed by sputtering indium tin oxide on the upper surface of an insulating transparent film such as a polyethylene terephthalate (PET) film to form a transparent conductive film, and a cyanoethyl resin or vinylidene fluoride resin is formed on the transparent conductive film. A high-dielectric resin such as a copolymer rubber is dissolved in an organic solvent such as dimethylformamide or N-methylpyridone, and a light-emitting layer in which a light-emitting body such as zinc sulfide is dispersed is printed by pattern printing by screen printing or the like, and a light-emitting layer is formed. A dielectric layer in which a high dielectric material such as barium titanate is dispersed in the same resin as the light emitting layer, a back electrode layer with carbon resin paste or silver resin paste, and an insulating coating layer with insulating paste. Each pattern was formed by printing and drying.

[0004]

The emission brightness of the EL lamp is proportional to the relative permittivity of the light emitting layer and the dielectric layer. As the high dielectric insulating resin used for the light emitting layer and the dielectric layer, cyanoethyl resins such as cyanoethyl cellulose and cyanoethyl pullulan have the highest relative permittivity among the commercially available ones, and high brightness EL can be obtained. You can

However, the cyanoethyl resin has a high hygroscopic property and absorbs moisture in a high humidity to significantly reduce the insulation resistance value, resulting in a large loss power, and a drawback that the luminescence brightness is reduced in an inverter circuit having a limited capacity. was there.

On the other hand, although vinylidene fluoride resin and vinylidene fluoride copolymer rubber have very little hygroscopicity and do not have the above-mentioned drawbacks, it is difficult to obtain high brightness because the relative dielectric constant is not as high as that of cyanoethyl resin. was there.

The dispersion type EL lamp is characterized in that it is thin and illuminates in a plane, but the planar shape as a set of point emission of individual phosphor powders dispersed in the resin in the phosphor layer. Since it emits light, there is a problem that the luminance is microscopically uneven.

The present invention solves the conventional problems as described above, and provides an EL lamp which can obtain high brightness, has no decrease in brightness in high humidity, and has less uneven brightness microscopically. The purpose is to do.

[0009]

In order to solve the above-mentioned problems, the present invention selects an insulating resin forming a light emitting layer from vinylidene fluoride resin or vinylidene fluoride copolymer rubber, and Ultrafine particles which are smaller than the wavelength of visible light and which can increase the relative dielectric constant of the light emitting layer are added and dispersed in the resin.

As a result, there is no drawback that the brightness is lowered due to moisture absorption in a high humidity atmosphere, and since the relative dielectric constant of the light emitting layer is increased, the light emitting powder efficiently emits light to obtain high brightness. Due to the light scattering effect of the fine particle high-dielectric powder, microscopic uneven brightness is reduced.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is to form a transparent electrode layer on the entire surface or in a predetermined pattern on an insulating transparent film, and stack the transparent electrode layer to form a light emitting layer in a predetermined pattern. Print and form a dielectric layer in a predetermined pattern on the light emitting layer, print a back electrode layer in a predetermined pattern on the dielectric layer, and connect one end to the back electrode layer and A first collector electrode whose end is printed and formed in a predetermined pattern so as to form an external connection portion of the insulating transparent film, and one end of which is connected to the transparent electrode layer and the other end of which is the insulating transparent film. A second collector electrode printed and formed in a predetermined pattern so as to form an external connection portion, and an insulating coat layer formed by printing so as to cover them on the entire upper surface except the tip of the external connection portion,
The average primary particle diameter is 5 in the insulating resin that constitutes the luminous body layer.
This is a structure in which ultrafine particle high-dielectric powder having a relative dielectric constant of 90 nm or more and 90 nm or less is dispersed. High brightness is obtained because the phosphor powder can emit light, and since the particle size of the ultrafine particle high-dielectric powder is sufficiently smaller than the wavelength of visible light, it simultaneously transmits the light emitted by the phosphor. Since it scatters light, it has an effect of obtaining an EL lamp with less uneven brightness even when observed microscopically.

According to a second aspect of the present invention, in the invention according to the first aspect, the insulating resin forming the light emitting layer is a vinylidene fluoride resin or a vinylidene fluoride copolymer rubber, and the ultrafine particles have a high dielectric constant. The amount of the conductive powder added is 5 to 65% by weight with respect to the insulating resin.
In addition to the effect according to the invention of claim 1, there is an effect that an EL lamp which is extremely stable with respect to the environment can be obtained without a decrease in brightness in high humidity.

An embodiment of the present invention will be described below with reference to FIG. (Embodiment 1) FIG. 1 is a sectional view showing the structure of an EL lamp according to a first embodiment of the present invention. As shown in FIG. Polyethylene terephthalate (hereinafter PET
The conductive indium oxide thin film is sputtered on the film to form the transparent electrode layer 2, and the following pastes are screen-printed in a predetermined pattern and dried repeatedly to be repeatedly applied.

Luminescent layer 3; a resin solution 1 in which vinylidene fluoride copolymer rubber (G-501 manufactured by Daikin Co., Ltd.), which is an insulating resin 9, is dissolved in isophorone so as to be 30% by weight.
17 g of BaTiO ₃ which is an ultrafine particle high dielectric powder 8
(BT-01 manufactured by Sakai Chemical Industry; average particle diameter 110 nm) 1
5 g of the paste was added and dispersed by a three-roll mill, and 150 g of the luminescent material 7 (TYPE 40 manufactured by Sylvania, USA) was dispersed by stirring to a dry film thickness of 35 μm. Dielectric layer 4; vinylidene fluoride copolymer rubber (manufactured by Daikin) G-501) was dissolved in isophorone in an amount of 30 wt% to 30 g of a resin solution, 41 g of BaTiO ₃ (BT-10 manufactured by Sakai Chemical Industry Co., Ltd.) powder was added, and the paste was dispersed with three rolls to give a dry film thickness of 35 μm. Back electrode layer 5; Conductive paste (Toyobo DW-250
H) has a dry film thickness of 10 μm and an insulating coating layer 6; an insulating paste (XB-804A manufactured by Fujikura Kasei) has a dry film thickness of 30 μm.

The above layers were stacked and printed and dried to produce an EL lamp shown in the sectional view of FIG. 5A is a current collecting electrode connected to the back electrode layer 5, and 5B is a current collecting electrode connected to the transparent electrode layer 2. 1 for this collector electrode 5A, 5B
When 00V 400Hz is applied, the initial brightness is 71 Cd /
It was m ² and was uniform with almost no microscopic luminance unevenness. It was found that a conventional EL lamp in which ultrafine particles of BaTiO ₃ was not added and dispersed in the light emitting layer was 42 Cd / m ² , and a significantly high brightness was obtained.

Further, this sample was lit at 40 ° C. for 90 to 9
When it was left in a 5% RH tank and the decrease in brightness was measured, it was 50.
% Luminance half-life is 100 at 40 ° C 90-95% RH bath
It was 0 hours.

In the first embodiment described above, the insulating resin used for the light emitting layer is made of vinylidene fluoride-6-fluorinated propylene-4fluorinated ethylene copolymer rubber. It is also possible to use vinylidene-4fluorinated ethylene copolymer rubber, vinylidene fluoride-6-fluorinated propylene copolymer rubber or rubber copolymer resin instead of them.

In the first embodiment, the ultrafine particle high-dielectric powder used in the light-emitting layer is made of BaTiO ₃ as an example, but TiO ₂ (rutile type) or BaTi _x Zr is used.
_(1-x) O ₃ , PbNb ₂ O ₆ , KNbO ₃ , PbTa ₂ O ₆ ,
PbTiO ₃ , Pb (Mg _1/3 Nb _2/3 ) O ₃ , PbZrO
_{The same} operation can be performed using a ferroelectric material such as _3- PbTiO ₃ .

The relative dielectric constant of the light emitting layer when the ultrafine particle high-dielectric powder is dispersed in the insulating resin is higher as the relative dielectric constant of the high-dielectric powder is higher, but the ratio of the insulating resin to be dispersed is higher. If the dielectric constant is not higher than at least one order, the relative dielectric constant of the light emitting layer cannot be effectively increased. Since the vinylidene fluoride resin and the vinylidene fluoride copolymer rubber have a relative dielectric constant of about ε = 7 to 13, it is necessary that the ultrafine particle high dielectric powder has a relative dielectric constant of at least 90 or more.

(Second Embodiment) In the first embodiment,
BaT, which is an ultrafine particle high-dielectric powder 8 for the vinylidene fluoride-based copolymer rubber which is the insulating resin 9 of the light emitting layer 3.
The weight ratio of iO ₃ is 30% by weight, but the light emitting layer is formed by changing the weight ratio of the ultrafine particle high dielectric powder BaTiO ₃ as follows, and the EL layer is formed in the same manner as in the first embodiment.
Lamps are manufactured and 100V40 of each EL lamp
The brightness at 0 Hz was measured. The results are shown in (Table 1).

[0021]

[Table 1]

(Third Embodiment) In the first embodiment,
Ultrafine particle high dielectric powder 8 dispersed in vinylidene fluoride-based copolymer rubber, which is the insulating resin 9 of the light emitting layer 3, B
The average primary particle diameter of aTiO ₃ was 110 nm,
Substitute for BaTiO ₃ powder or TiO ₂ powder having various average particle diameters shown below and add and disperse them to form a light emitting layer, and manufacture EL lamps in the same manner as in Embodiment 1 to prepare EL lamps. The brightness at 100 V and 400 Hz was measured. The results are shown in (Table 2).

[0023]

[Table 2]

[0024]

As described above, according to the present invention, it is possible to obtain an EL lamp having high brightness, little unevenness in brightness microscopically, and extremely stable brightness even in a high humidity atmosphere.

[Brief description of drawings]

FIG. 1 is a sectional view of an EL lamp according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating transparent film 2 Transparent electrode layer 3 Luminous body layer 4 Dielectric layer 5 Back electrode layer 5A, 5B Current collecting electrode 6 Insulation coating layer 7 Luminescent body 8 Ultrafine particle high dielectric powder 9 Insulating resin

Claims (2)

[Claims] 1. A transparent electrode layer is formed on the entire surface or in a predetermined pattern on an insulating transparent film, a light emitting layer is printed on the transparent electrode layer in a predetermined pattern, and is laminated on the light emitting layer in a predetermined pattern. The body layer is formed by printing, and the back electrode layer is formed by printing in a predetermined pattern on the dielectric layer. One end is connected to the back electrode layer and the other end constitutes an external connection portion of the insulating transparent film. The first current collecting electrode printed and formed in a predetermined pattern as described above, and one end connected to the transparent electrode layer and the other end printed and formed in a predetermined pattern so as to configure an external connection portion of the insulating transparent film. A second current collecting electrode and an insulating coating layer formed by printing so as to cover the entire upper surface of the external connection portion excluding the tip of the external connection portion. The primary particle diameter is 500 nm in the insulating resin forming the light emitting layer. Less than An EL lamp in which ultrafine particles with a relative dielectric constant of 90 or more and high dielectric powder are dispersed. 2. The insulating resin forming the light emitting layer is vinylidene fluoride resin or vinylidene fluoride copolymer rubber, and the addition amount of the ultrafine particle high dielectric powder is 5 relative to the insulating resin. The EL lamp according to claim 1, which is about 65% by weight.