JPS61161691A - Field light emitting lamp - 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 Industrial Application) The present invention relates to an electroluminescent lamp that can be used for liquid crystal backlights, display devices of various shapes, and the like.

(Prior Art) Conventionally, as an electroluminescent lamp, one having a structure in which a transparent conductive film, a light-emitting layer, and a back electrode are sequentially formed on the surface of a synthetic resin base material having light transparency is known. This electroluminescent lamp excites an electroluminescent phosphor to emit light by applying a voltage between a transparent conductive film and a back electrode.

(Problems to be Solved by the Invention) However, in the conventional product described above, the adhesion between the transparent conductive film and the luminescent layer is weak, and a peeling phenomenon (so-called "electrode peeling") occurs at the interface between the two. was there.

If peeling occurs at the interface between the transparent conductive film and the light emitting layer, even if it is only local, the electrical resistance between the electrodes will increase due to the decrease in the contact area, and as a result, This has the disadvantage of causing a decrease in the light emission detection rate of the light emitting lamp.

(Means for Solving the Problems) In view of the above-mentioned current situation, the inventors of the present invention have made extensive studies and found that by interposing a high dielectric layer between the transparent conductive film and the light emitting material, the transparent conductive film and the light emitting material can be It was discovered that the adhesion of the layers could be improved and electrode peeling could be prevented, leading to the completion of the present invention.

That is, the present invention relates to an electroluminescent lamp characterized in that a transparent conductive film, a high dielectric thin film, a light emitter layer, and a back electrode are sequentially laminated on the surface of a synthetic resin base material having light transparency. It is something.

The light-transmitting synthetic resin base material used in the present invention is usually in the form of a film or sheet with a thickness of about 50 to 200 μm, and the light transmittance is preferably set to about 60% or more. However, in some cases, a material with a smaller light transmittance than this may also be used.

This synthetic resin base material is made of polyester, polycarbonate, polyethersulfone, polyamide, polystyrene,
Polyacetal, polyolefin, polyacrylonitrile, ABS [fat, thermoplastic resin or solvent-soluble resin such as polyurethane, or thermosetting resin such as epoxy resin, allyl ester resin, silicone phenol resin, unsaturated polyester resin, melamine resin, urea resin, etc. It can be formed from

The surface of the synthetic resin base material is made of indium oxide, tin oxide, a mixture of indium oxide and tin oxide, gold, silver, copper, aluminum, palladium, platinum, etc., and is transparent in the visible light range and conductive. A transparent conductive film functioning as an electrode is formed having a thickness of usually about 50 to 100 OA.

The transparent conductive film can be formed on the surface of the synthetic resin base material by a conventionally known vacuum deposition method, sputtering method, ion blating method, or the like.

In the present invention, a light-transmissive, high dielectric thin film having a high dielectric constant is formed on a transparent conductive film. The light transmittance of the high dielectric thin film may vary depending on the synthetic resin base material, but it is usually about 70% or more, and the dielectric constant is usually about 100 or more.

This high dielectric thin film is formed by reactive vapor deposition or reactive sputtering of Ti5Si and Zr.
02, Method of forming Zr0z R film, Ti0z, 5i
02, a method of forming the metal oxide thin film by a PVD method such as RFx battering or electron beam evaporation using ZrO2 or Ta205, an organic titanium compound such as an alkyl titanate compound, an organic silicon compound such as tetraethyl silicate, or an organic zirconium A method of forming a metal oxide thin film using a compound by a coating method or a CVO method can be used.

The thickness of the high dielectric thin film is preferably about 50 A to 5 μm. If the high dielectric thin film is too thin, it will not be a continuous and uniform film, and no effect can be expected; if it is too thick, the luminance of the electroluminescent lamp may be reduced.

In the present invention, a high dielectric thin film is formed on the transparent conductive film in this way, and there is a concern that the formation of the high dielectric thin film will reduce the light transmittance on the synthetic resin base material side. There is almost no decrease in light transmittance.

A light emitter layer and a rear m-pole are further formed in this order on the high dielectric thin film.

The phosphor layer emits light upon application of a voltage, and can be formed, for example, from a mixture of a phosphor and a dielectric polymer as a binder, and its thickness is usually about 20 to 100 μm.

The phosphor is made of lead sulfide, zinc selenide, mixed crystal of zinc sulfide and cadmium sulfide as a main ingredient, metal powders such as copper, silver, gold, manganese, etc. as an activator, and chlorine as an activator. A mixture containing a halogen such as bromine or iodine or a metal powder such as aluminum or gallium can be used. In this case, the mixing ratio of the base agent, activator, and activator is usually 0.01 parts by weight of the activator to 100 parts by weight of the base agent.
~0.1 part by weight, and 1 to 3 parts by weight of the activator. ”
In addition, examples of polymeric dielectric materials used as binders include cellulose resins such as cyanethyl cellulose, fluororesins such as polyvinylidene fluoride and copolymers containing vinylidene fluoride, epoxy resins, unsaturated polyester resins, organosilicon resins, and melamine. Resin, urea resin, polyurethane resin, etc. can be used.

The mixing ratio of the phosphor and the polymeric dielectric as components for forming the phosphor layer may vary depending on various conditions, but is usually 50 to 600 parts by weight of the phosphor to 100 parts by weight of the polymer dielectric. .

The phosphor layer is made by dissolving polymeric dielectric powder in an organic solvent such as acetone, methyl ethyl ketone, dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, etc., dispersing the phosphor powder in this solution, and dispersing the phosphor powder in this solution. is applied onto a high dielectric thin film, the solvent is removed by heating, and the dielectric is heated above the melting point or curing temperature for a predetermined period of time to form a high dielectric material by thermal fusion or curing of the dielectric. This can be done by forming a layer on a thin film.

In the present invention, a back surface [9] is formed on the light emitter layer.

The back electrode is formed by, for example, placing a metal foil such as aluminum or copper foil on the luminescent material forming component layer t after removing the organic solvent during the formation of the luminescent layer, and then heating it to firmly place it on the luminescent layer. Can be laminated and integrated.

The electroluminescent lamp of the present invention can be produced by, for example, (a) forming a transparent conductive film, a high dielectric thin film, a light emitter layer, and a back surface [pole] in sequence on the surface of a synthetic resin base material; A member in which a transparent conductive film and a high dielectric thin film are sequentially formed on the surface of the material, and a member in which a luminescent layer is formed on the surface of the back electrode are prepared. It can be obtained by stacking them facing each other and applying heat and pressure.

In the present invention, an insulating layer can be interposed between the light emitting layer and the back electrode if desired.

This insulating layer is formed of the same type of polymeric dielectric material used in forming the light emitting layer (barium titanate, if desired).
A material having a high dielectric constant such as titanium oxide can be mixed therein is preferable from the viewpoint of adhesion between the insulating layer and the luminescent layer.

Next, the present invention will be explained in detail with reference to the drawings. In the electroluminescent lamp shown in the drawing, 1 is a synthetic resin base material, on one side of which are coated a transparent conductive film 2, a high dielectric thin film 3, and a luminescent layer 4.
, an insulating layer 5 and a back electrode 6 are sequentially laminated.

In this light emitting lamp, when a voltage is applied between the transparent conductive film 2 and the back electrode 6, the light emitter layer 4 emits light.

Note that the insulating layer 5 can be omitted, but the light emitter R4
Luminous efficiency, luminance, and luminescent layer 4 and back electrode 6
It is desirable to provide this in order to improve the adhesion with the

In the present invention, a high dielectric thin film 3 is interposed between the transparent conductive film 2 and the light emitter 4, and by doing so, the adhesion between the transparent conductive film 2 and the light emitter @4 can be improved. can.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 I was coated on one side of a 75-m thick transparent polyethylene terephthalate film with an Sn content of 10%.
Using an n-Sn alloy as a target, a transparent conductive film with a thickness of 200 A is formed by a reactive magnetron sputtering method with oxygen.

Next, an alkylzirconium solution (manufactured by Nippon Soda Co., Ltd., trade name Atron NZr') is applied to the transparent conductive film.
Heat at a temperature of 80° C. for 30 minutes. This heating removes the solvent and decomposes the alkylzirconium, forming a zirconium oxide thin film (high dielectric thin film) with a thickness of 2000 A.

Thereafter, the phosphor powder was dispersed in an acetone solution of cyanoethyl cellulose as a binder, and this liquid was applied onto the zirconium oxide thin film by screen printing.
By heating at 60° C. for 120 minutes, and further increasing the temperature to 150° C. and heating for 2 minutes, a phosphor layer with a thickness of 60 am is formed. As the phosphor powder, a powder containing lead sulfide as a main component was used, and the blending ratio (weight ratio) of the powder and cyanoethyl cellulose was 84:16.

Next, barium titanate powder is dispersed in the same atocene solution of cyanoethylcellulose as described above and applied onto the luminescent layer. The blending ratio c (weight ratio) of barium titanate and cyanoethyl cellulose was 1:1.

The temperature was raised to 150°C and heated for 2 minutes to form an insulating layer, and an aluminum foil (back electrode) was attached to the insulating layer to form the same structure as shown in the drawing. Obtained an electroluminescent lamp.

The adhesive force between the transparent groove wLII film and the luminescent layer in this electroluminescent lamp was 200011/25 m-width, and the adhesion strength between them was great.

The above adhesive strength was obtained by bonding the back electrode of an electric light emitting lamp to a 2+a+ thick iron plate using epoxy adhesive at a temperature of 25°C.
This value was measured by peeling at the interface between the luminescent layer and the zirconium oxide thin film as a high dielectric thin film using a 180° peeling method at a peeling rate of 50 mn/min.

For comparison, an electroluminescent lamp was obtained in the same manner as above except that a zirconium oxide thin film (high dielectric thin film) was not formed, and the adhesive strength between the transparent conductive film and the luminescent layer in the lamp was evaluated. When measured in the same way, it was 700 i/2
The width was 5 m, and the adhesion between the two was small.

Example 2 One side of a 75 μm thick polyethylene terephthalate film was coated with 1n203 (5% by weight of 5n02).
A lower oxide film is formed by an electron beam evaporation method using a carbonaceous material as a target, and the film is annealed by heating at a temperature of 170° C. for 10 minutes in the air to form a transparent conductive film.

Next, a high dielectric thin film with a thickness of 1000λ is formed on the transparent conductive film t by RF sputtering using Ta205 as a target.

Separately, 100 parts by weight of epoxy resin and 200 parts of titanium oxide powder were added to a 200 μm thick aluminum foil.
A mixture consisting of parts by weight is spread and heated at a temperature of 100° C. for 1 hour to form an insulating layer with a thickness of 10 μm.

A liquid prepared by dispersing phosphor powder in an acetone solution of an epoxy resin as a binder is applied to this insulation ah using a silk screen printing method, and heated at a temperature of 100°C for 5 minutes. Forms body layers. As the phosphor powder, a green-emitting phosphor containing a mixture of zinc sulfide (base ingredient), copper (activator), and aluminum (activator) was used.

Thereafter, the member consisting of the polyethylene terephthalate film, the transparent conductive film, and the high dielectric thin film, and the member consisting of the aluminum foil, the insulating layer, and the luminescent layer are stacked together with the high dielectric thin film and the luminescent layer facing each other. , 11 layers were integrated using a roll laminator (temperature: 150° C.) to obtain an electroluminescent lamp.

The adhesive force between the transparent conductive film and the luminescent layer in this electroluminescent lamp was 1800 g/25-+ width, and the adhesion strength between the two was high.

For comparison, an electroluminescent lamp was obtained in the same manner as above except that no high dielectric thin film was formed, and the adhesive strength between the transparent conductive film and the luminescent layer in the lamp was ρθF/25M.
The width was small, and the adhesion between the two was small.

(Effects of the Invention) In the present invention, by interposing a high dielectric thin film between the transparent conductive film and the luminescent layer, the adhesion between the two is improved, so that electrode peeling can be effectively prevented.

[Brief explanation of the drawing]

The drawing is a front view showing an example of the electroluminescent lamp according to the present invention. 1...r・Synthetic resin base material 2...Transparent conductive film 3...High dielectric thin film 4...
... Luminous layer 5 ... Insulating layer 6
・・・・・・・・・Rear electrode patent issuer Hijikata Mibe, representative of Nitto Electric Industry Co., Ltd. / - Trowel Silk base material 2 - Transparent FIF 4 conductive term 3 - High electromagnetic interference thin film 4 - A 1 Cup 1 Tar-ratio #C Shoulder 6- Kenmen Viewing

Claims (1)

[Claims] An electroluminescent lamp characterized in that a transparent conductive film, a high dielectric thin film, a light emitter layer, and a back electrode are sequentially laminated on the surface of a synthetic resin base material having light transparency.